l This Is Smart Steelworks

As addressed in the POSCO the Lighthouse Factory #1, a smart steelworks collects and standardizes all factory data via PosFrame; then, the PosFrame self-learns the data to provide optimal process conditions and controls the various operations at steelworks.

The smart process minimizes the occasions for heuristic decisions preventing human errors. Objective and accurate data can lead to a eureka moment where innovative solutions are discovered. Wait, does this mean human labors are now dispensable?

Such hasty assumption is a surefire way to creating unnecessary anxiety. What the smart technology does is to let the workers delegate simple repetitive tasks to the machine, instead channeling their sophisticated skills and mental energy into perfecting the steelworks operation. The workers feed the result back into the PosFrame fostering the ultimate synergy between technology and humans.

How did smart technology transform the steelmaking operations at steelworks? Let’s find out.

[Order process] Small Lot Orders Go Smart

POSCO’s Order Management Group handles the planning for the entire steel production. One of their crucial tasks includes processing small lot orders — the order quantity for these small lot orders is too small that they typically do not meet a steelworks’ minimum production volume requirements.

Before smarticization, workers manually analyzed and processed the small lot orders — from checking the small lot order standards to figuring out whether and how to bulk-process chunks of small lot orders. The workers manually set the standards and modified them every half-year, the worst-case scenario being small orders sometimes ended up buried and left out. Some urgent orders were constantly classified as ‘small lot’ orders never receiving greenlight for production. In such cases, the order setting had to be reset so it can be incorporated with other orders. This used to take almost six hours or more. The average time for processing the entire small lot order is about 12 hours.

With ‘Smart Task,’ AI automatically organizes small lot orders — based on the analysis of all previous data, the system derives 12 factors impacting small lot orders. The AI also self-learns, so it can self-evaluate the orders. The processing accuracy is currently at 97%. To minimize production costs, the system also predicts the planning volumes so that small lot orders can be integrated with other orders — the production accuracy for which is at 99.99%. Compared to the previous 12 hours, the new procedure takes only an hour.

[Ironmaking] POSCO’s Smart Ironmaking Becomes the National Core Technology

The Smart Task comprehensively controls multiple factors such as furnace ventilation, combustibility, molten iron temperature, etc.; whereas, in the past, all of these were left to manual labor.
For the smooth operation of the Smart Task, the ironmaking department at Pohang Steelworks first defined variables that impact the furnace condition and subsequently integrated various information. In technical terms, this process is called ‘standardizing data.’

Under the Smart Task system, various indicators that were previously subject to the workers’ heuristic knowledge have been organized automating the manual processes. Now, the temperature of molten iron becomes data through IoT, and high-definition cameras conduct regular check-ups on raw materials and fuels.

POSCO started accelerating the establishment of an auto-control system in 2017. Through deep learning, AI self-learns, predicts and manages the data. Beyond simple automation of the current tasks, the system predicts and controls the potential variables and derives optimal results.

Even if the current furnace condition is satisfactory, the smart system goes above and beyond to make sure the furnace maintains its optimal condition. The Pohang No.2 blast furnace became a testing ground for the automated smart technology for the first time in Korea upping the daily molten iron production by 240 tons. The smart technology applied to the Pohang No.2 blast furnace received the government designation as the National Core Technology in July this year.

[Steelmaking] POSCO Goes PTX: Posco sTeelmaking eXpress!

The extremely high temperature required for steelmaking operation makes it difficult to measure temperature in real-time, which was why the daily operation was entirely dependent on field workers’ heuristic knowledge. Variations and human errors were inevitable in this system. Abnormalities at stages required not only a full-stop of the procedure directly involved — but also the procedures before and after.

The steelmaking Plant 2 at Pohang Steelworks has developed an integrated control system — it controls the timing, temperature, and the ingredients from the converter to the continuous casting process. There are potentially 125,000 probable procedures involved in the production for any given steel product.

POSCO digitized and standardized these procedures completing the PTX system by July 2018. With PTX, continuous processing became a reality — from converter through continuous casting without temporary halts or delays. Live-assessment of estimated arrival time, temperature, and product components also became available.

Before PTX, the temperature accuracy was at 80%, but now the system predicts the temperature with 90% accuracy. The use of raw materials also became more efficient.

[Continuous Casting] Prediction Made Simpler and Faster, Saves 600 million

Quality control is absolutely crucial, but it’s impossible to go through each and every material with a fine-tooth comb. So the typical inspection involved a through, 100% surface inspection of sample materials. If and when any abnormalities were detected in the particular sample, all other materials produced in the same batch had to be retrieved, subsequently undergoing thorough inspections.

The Pohang Steelworks No.2 and No.4 continuous casting plants annually inspected 340,000 tons of sample materials — only 30,000 tons found to be defective.

With a relatively small amount of defective materials, POSCO strove to minimize the time wasted, and to maximize the company’s resources. By applying artificial intelligence, POSCO collected a vast amount of data on steelmaking and continuous casting processes thereby establishing a model to predict defects. This was done by creating criteria of what constitutes as abnormalities in quality. Since the adoption of the new system in March 2018, the system now only screens defective materials, eliminating unnecessary testings. Furthermore, it pinpoints the reasons for the defect — the new system is expected to save over 600 million KRW every year.

[Rolling] AI Analyzes and Auto-controls Flatness Factors

Thick plate products first undergo the slab-heating process subsequently going through two rolling procedures. After that, according to the customer’s requirements, it undergoes an accelerated cooling process called Thermo-Mechanical Control Process (TMCP). TMCP involves spraying high-speed water on a steel plate rapidly cooling it to a designated temperature to improve the strength and the welding capacity of steel products. The process requires special equipment — and the water-spraying technology is highly advanced. Without accurate maneuver, the flatness of a steel product can be compromised.

In the past, the flatness of thick plates was manually analyzed, twice — once when the plate was hot (hot flatness) after TMCP treatment; and again, when the plate cooled down (cold flatness) during the shearing process. Measuring flatness in such a manner was extremely time-consuming, and it often caused a functional overload — it was challenging for the factory engineers to control the TMCP by manually inputting the results one at a time.

The plate plant at Gwangyang Steelworks created a learning model by analyzing the influential factors for hot and cold flatness — ultimately the company figured out the conditions that can achieve the most optimal flatness. Now, the engineers can simply monitor the optimal working condition values produced by AI supervising the smooth operations of each process. The correction needs for the products during the post-TMCP process are now reduced to 50% which saves about 1.3 billion KRW annually.

[Surface Treatment] Another National Core Technology, POSCO Surface Treatment Goes AI.

Continuous Galvanizing Line (CGL) involves processing cold-rolled coils with continuous heat treatment, putting them in zinc pot, ultimately producing galvanized iron plates. POSCO’s Giga Steel is also produced through CGL process.

After plates are taken out the zinc pot, an air knife controls the coating amount by cutting out zinc before it solidifies on the surface. The target coating weight varies for each product, and the coating weight could be measured only after the air knife procedure and solidification completed. This is why the live-control of coating weight remained challenging.

To address the challenge, POSCO developed AI-based control model for coating weight — it uses deep learning for precise management of such factors as steel grade, plate thickness, width, operating conditions, and target coating weight. Previously, the accuracy rate for predicting coating weight was projected at 89% — now, with 99% accuracy, the technology has been applied to all surface treatment plants at both Pohang and Gwangyang Steelworks. Just as POSCO’s smart ironmaking technology, POSCO’s smart surface treatment technology also received government designation as National Core Technology.

l Smart Steelworks Enhances Safety

A truly smart steelworks operation prioritizes workers’ safety as well as the environment. POSCO is no exception. What makes POSCO exceptional in this domain, especially when it comes to its application of smart technology, is the way the company utilizes smart CCTVs. POSCO developed a smart CCTV system — unlike general CCTVs which simply record video footage, POSCO’s smart CCTV auto-detects patterns and movements at production facilities. When the system recognizes any abnormalities, it promptly alerts the administrator in charge.

POSCO developed an optimized smart CCTV system that meets various demands of steelworks operations by integrating previously accumulated footages. From last year, POSCO began installing the smart CCTVs at Gwangyang No. 3 surface treatment plant, No.2 steelmaking plant, No.1 coke plant, and Pohang No. 2 plate plant.

Smart CCTVs automatically recognizes and analyzes various information such as the product quality and safety information, reducing the amount of time workers merely ‘stand by’ just to check all the information manually. At a steelmaking plant, for example, smart cameras can measure the temperature of molten iron. At a surface treatment plant, the smart camera detects the subtle color difference of coil-ends allowing prompt response for potential quality defects.

Furthermore, multiple imaging devices, such as thermal imaging cameras, can proactively detect and prevent fire hazards. At all corners of POSCO steelworks, smart CCTVs gather information and identify potential hazards before anybody does.

POSCO’s smart steelworks is an ongoing project. With the establishment of smart technology, POSCO will continue to address the challenges remain unsolved — POSCO aspires to complete the smartization process to ensure production efficiency, top quality products and improved safety.

POSCO is the first South Korean company to receive such recognition. Through its smart-factory platform, the company demonstrated its ability to leverage artificial intelligence to drive productivity and quality improvements in the steel industry.

How does POSCO drive impact by applying Fourth Industrial Revolution technologies? POSCO Newsroom reports.

l POSCO the Lighthouse Factory Shines Light on Manufacturing Industry

Lighthouse factories represent a range of industries that demonstrate leadership in applying Fourth Industrial Revolution technologies like IoT, cloud computing, Big Data, and AI, to drive financial and operational impact.
For the last five years, POSCO has laid the groundwork for the smart factory to boost its competitiveness in steelmaking. POSCO’s selection signifies global recognition of the company’s such effort.
From the submission of the application, due diligence, to documentation review by WEF consultant, the lighthouse factory selection is an arduous process. From the initial application submission, it took POSCO about one year until its final selection as the lighthouse factory.

One of POSCO’s esteemed contributions was its establishment of a sound ecosystem where SMEs and start-ups can thrive through active collaboration. Additionally, POSCO’s smart factory platform was customized to meet the needs of the steel industry. One of the WEF consultants at POSCO’s steelworks was especially impressed with the way in which years of human skills paired superbly with the new AI technology in monitor-controlling the massive furnace operations live, 24/7.

There are altogether 26 lighthouse factories around the world including POSCO, Siemens, BMW, Johnson & Jonson, and Haier. The lighthouse designation effectively gives the companies the Global Lighthouse Network membership among which the members share their knowledge and experiences enhancing their ability to better-adopt smart-factory platform. POSCO plans to utilize the benefits the Network offers to boost its ability to establish and advance smart factories that meet ever-changing industry demands.

l Sophisticated Steelmaking Goes ‘Smart’

Heavy pole and massive chimneys are some of the things that people associate with typical steelworks operation. What’s so complicated about steelmaking? — isn’t it all about stuffing everything in the blast furnace where molten iron comes out? Then molding the molten iron, baking it, pressing it, and cutting it up?

Maybe so, but in actuality, each process is extremely sophisticated especially when combined with varying customer requests. The smooth operation of POSCO’s 24/7 steelworks can be attributed to the company’s 51 years of experience as well as to the field engineers whose meticulous monitoring and management of the steelworks operation propel the steelworks operation forward.

Even with their expertise, however, each engineer’s experience varies. In the immense intricacy of steelworks operation, POSCO must deal with the inevitable at all times. What are some of the inevitable situations that can occur during the steelmaking process?

Production Planning: POSCO’s ‘Order Management Group’ is the brain of all steelworks operation — not only does it take orders, but it also manages production schedules, locations, and production methods. The Group is also in charge of figuring out precise production timing as per special customer requirements. Some customer requests involve a unique mixture of ingredients, so there are always many variables to consider. There are at least 10 ‘standard’ procedures the Order Processing Group must consider. Only after these minimum standards have been met, the steelworks operation of that specific order can receive greenlight.

Ironmaking: POSCO Newsroom previously covered the basic concept of managing ‘blast furnace condition’ in the ‘Blast Furnace Anatomy #1 — To the Heart of Steelworks Operation’ (LINK). There are countless tasks involved in 24/7 blast furnace operation — from maintaining temperature, placing in fuels and raw materials with precision, to predicting the amount of by-product gas generation.

Steelmaking & Continuous Casting: The steelmaking department removes impurities from the molten iron produced in the previous ironmaking stage, by way of converter — the molten iron becomes ‘steel’ in this process. During the casting process, the ‘steel’ is molded into intermediary materials like slab, bloom, and billet.

Molten iron can be made into countless different products to meet diverse customer needs, each requiring different portion and mixture of ingredients. To achieve this goal, the molten iron undergoes four different stages of ‘blowing process’ where oxygen is pressured through molten iron to lower the carbon content of the alloy, changing it into low-carbon steel.

At this point, the molten ‘steel’ goes through continuous casting, after of which is cooled down and cut. Temperature and ingredient management with precision is crucial for maximized use of limited resources.

Rolling: The next step is ‘tempering,’ a process of heat treating, which is used to increase the toughness of iron-based alloys. In ‘Game of Thrones’, blacksmiths constantly bang on the iron as a way of hardening the material. In steelworks, the process of rolling achieves the same goal.

In rolling, materials are passed through the rotating rolls to produce steel products that meet customer demands: in thickness, width, strength, durability, etc. Imagine baking bread, each with a different requirement for textures, tastes as well as shapes.

Surface Treatment: Automotive steel plates and home appliances are galvanized so that they become more corrosion-resistant, more suitable for various manufacturing purposes. Precise surface treatment suited to each purpose is the key to an advanced coating technology.

Notwithstanding the 100% effort aimed for perfection, complex steelmaking process overflows with information. Variation — be it human or mechanic — is inevitable in each and every step of the process. To address such variation, POSCO is opting for the smart factory, identifying it as the next-generation of its growth engine.

The establishment of smart factories must be preceded by the digitization of factories. Through Process Innovation Project (PI Project) in the 2000s, POSCO successfully achieved digitization of its factories. What set POSCO apart from the various similar endeavor is that the company has been working this digitization muscle for a while now. Smart factory, which is being built on the digital factory, is at the center of POSCO’s unique smart factory platform called PosFrame.

l PosFrame, the Foundation of POSCO’s Smart Factory

What is the origin of POSCO’s smart factory? It can be traced back to the year 2015 when the hype of smart industry hasn’t quite caught on the flame. Even back then, POSCO introduced new technologies like Big Data, specifically at the Plate Plant at Gwangyang Steelworks. At this point, Gwangyang became a testing ground for POSCO’s smart factory. During this process, the foundation for ‘PosFrame,’ POSCO’s unique smart platform, was created.

With PosFrame, POSCO could establish a system in which the company’s countless data and skills accumulated through the 51 years of its operation can be integrated and stored in one place.

How is this different from conventional digitization?

PosFrame is the world’s first smart factory platform specified for continuous manufacturing processes. The reason why ‘PosFrame’ is identified as a ‘platform’ is this: think of railway platforms. Railway platforms are where different types of trains pass through — be it bullet trains, express trains, or slower all-stop trains. A platform manages information about different types of trains — in this case, data — coming and going all the time. It’s a perfect system for 24/7 steelworks operation. The goal of PosFrame is to pinpoint the reason behind a product defect, if and when, by meticulously back-tracing the steelmaking process to figure out exactly where a variation might have occurred.

Furthermore, PosFrame goes beyond simple digitization. Whereas digitization simply stores information as data, PosFrame analyzes the data, enabling the development of automation models.
Here, a question might arise: isn’t automation something only reserved for experts? PosFrame’s ‘Workbench’ feature says no. Workbench is accessible to everyone. For example, field engineers can apply their expert knowledge and use the data to develop automation models so that the models can be utilized in various steelmaking processes. Thanks to the data collected and standardized by PosFrame, engineers can analyze information not only for the process they’re directly involved but also the processes that come before and after. PosFrame makes it easier for the engineers to tackle difficult issues that previously remained as random occurrences.

The incredibly accessible PosFrame accelerated POSCO’s advance into smart factories. Through PosFrame, all POSCO employees are turning into semi-AI experts.

To further its smartizaton process, POSCO has been providing smart tech training to all employees since 2017. The training is helping the employees take their skills to the next level towards establishing a more data-driven working environment.

Through the ‘POSCO the Lighthouse Factory #1,’ we introduced the core concepts behind POSCO’s smart factory. In the next episode, ‘POSCO the Lighthouse Factory #2: POSCO’s Smart Factory Transforms the Industry (The Cases),’ we will provide more concrete pictures on how POSCO’s smart factories operate. Stay tuned.

Now the ‘FE Odyssey: “I Am a ButterFEly.”’, the final installation of the Blast Anatomy series, will follow the iron (FE) through its journey – all the way from its birthplace in mine to its final destinations, right around us. Better yet, the FE itself will walk us through the entire adventure!

Like a majestic butterfly who muddles through arduous stages – eggs, caterpillars then pupa – the journey of steel is just as rigorous: from iron ore buried deep in the mines until it finally presents its true self, as steel.

Join now to follow the FE Odyssey. POSCO Newsroom presents: “Blast Furnace Anatomy #3 – FE Odyssey: “I Am a ButterFEly.”

l Into the World – Like a Butterfly Fighting Its Way out of the Egg,
Iron Ore Makes Its Way out of the Mine

▲ Roy Hill Mine, Western Australia

I was born in Roy Hill mine in Western Australia, over 6,500 kilometers away from Pohang where one of POSCO steelworks is located. While buried deep in the ground of Roy Hill, I always dreamed of transforming into cool and chic steel products – a sturdy car, a slick home electronics, or a shiny stainless travel mug that offers people warm beverages.

Roy Hill mine has a total of 2.3 billion tons of iron ore deposits. POSCO started investing in Roy Hill mining project since 2010 now holding 12.5% of its shares. Roy Hill boasts the annual production of 55 million tons of iron ores. It’s huge! And that’s how so many of my siblings come from there. Besides Roy Hill, my other iron ore siblings also come from places like Canada and Brazil.

From the mine, do I travel straight to steelworks? Not exactly. I wish it were that simple. Before I get transported to the port in Australia, I make a stop at a laboratory for thorough testing – all my internal organs undergo rigorous testing. Using magnets, the lab technicians classify ores with high iron (FE) content. Fortunately, the iron ore that housed me passed the inspection, and I headed to the harbor so I can be sent to Korea.

My siblings and I boarded the transport ships to Korea. After 15 days of a long journey across the ocean, I can hardly forget the excitement I felt when we finally docked. Here we were, at the pier for POSCO’s raw materials, and I was stepping closer to my dream. Every year, 55 million tons of iron ores reach the POSCO docks – both Pohang and Gwangyang combined! These iron ores all share one dream and one dream only – the dream of becoming steel.

After we disembarked from the ship, we got stacked in raw materials yard. The raw material yards at POSCO steelworks measure to be 1.85 million m² – both Pohang and Gwangyang combined.* In that vast field of POSCO yard, I met some new friends – some were called ‘coal.’ Later on, when we reunited in front of the blast furnace, the coal friends would stand before me already transformed as ‘coke.’ Because coal could produce acidic dust, they would first travel to a place called ‘silo,’ an eco-friendly storage facility specifically designated for them.

*The Seoul World Cup Park: 2.1 million m².

When I looked closely, I noticed my iron ore siblings all had very different body types. We were all jagged and uneven. So we got separated, tossed and rolled around a lot, so our bodies can be shaped just right for the furnace. It was a lot of work, but I was so psyched – I knew I would soon get to travel into the blast furnace!

l Rites of Passage for Butterflies, So for the Iron Ores

As it turns out, I knew nothing of what it took to become steel. From the raw materials yard, I thought I would head straight into the blast furnace. Little did I know that I had to undergo one last stage – a process called ‘sintering.’ I also went through several other processes and entered a hot oven. As I got baked in it, I got more polished and solid. It was 1,300℃, so it was super hot, but I heard it’d be even hotter inside a blast furnace, so I got through it okay. After sintering, I transformed into sinter, a raw material for steelmaking, not an ugly and unpolished iron ore anymore!

As sinter, I passed through three filters, and right in front of the rotation chute, I reunited with the friends I’ve met earlier at POSCO yard. We would enter the blast furnace together. Through the rotation chute, we twirled and rolled around, a lot.

I heard some of my friends didn’t quite make it to the rotation chute. They didn’t pass through the filtering stages earlier. But I heard they were going to be reused as raw materials for the sintering instead.
I entered the furnace as sinter, but there were other raw materials like ‘sized lump’ and ‘pellet’. The sized lump came in just the perfect size right from the extraction. Relatively small iron ores became pellets through compressing and molding. Subsidiary materials like limestones also entered the furnace with me. Of course, the crucial fuel friends like coke, who help us melt, also joined us.

Facing the blast furnace, I got so nervous, so I took a deep breath to calm myself down. Because the temperature inside the furnace could reach as high as 2,300℃, it was rather hard to breathe, but my coke friend and I patiently took turns forming layers inside the furnace. As time went on, we traveled down. As we traveled down, we could feel the hot air flying up. Along with the hot air, I flew up in the middle of the furnace. I wasn’t quite sure where I would go next. Meanwhile, I heard my coke friend shouting, “hot air slapping!”

The coke hot aired by 1,200℃ air from the bottom, was oxidized producing carbon monoxide as a result. In turn, this carbon monoxide took oxygen away from me. These series of chemical reactions separated me from oxygen, and I became pure iron, FE! I finally transformed into molten iron and dropped to the floor. Along with my siblings, I roared in victory and exited the furnace through the tap hole.

l How Molten Iron Becomes Steel

I became molten iron, but the excitement was short-lived. To become steel, I have yet to face another set of journeys. As is, right out of the furnace, I was called ‘pig iron’ still containing several impurities like carbon, phosphorus, and sulfur. I still had to go through several processes inside the steelworks to reborn as a slick and beautiful steel product. The processes to come were: steelmaking, casting and rolling.

POSCO’s Pohang and Gwangyang Steelworks are integrated steelworks – because they have all the facilities to turn something like me, a piece of iron ore rock, into perfect and complete steel – all in one place. Let me walk you through each step.

Step 01. Steelmaking process – removing impurities from molten iron, molten iron becomes molten steel at this stage.
To become steel, I still had to shed impurities completely, and my carbon proportion had to be adjusted also. As pig iron, I exited the furnace through the tap hole and got loaded onto the ‘Torpedo Ladle Car’ and transported to the converter.

At this stage, the steelworks workers called me ‘molten iron,’ which meant pig iron made in the blast furnace. The torpedo ladle car is a specially designed car that transports molten iron. Each car, which can load up to 300 tons of molten iron, heads to the converter. Once I got to the converter, I saw scrap metals as well as pure oxygen. The carbon inside me became oxidized, and its proportion was reduced down to 0.3%. At this stage, I became independent from all the unnecessary impurities. Through this steelmaking process, I became molten steel – pure and optimized pre-steel. I wasn’t yet complete but was a ‘steel’ nonetheless, finally!

Step 02. Casting process – where the liquidated steel becomes solid.
As molten steel, I went into a mold, and through the continuous casting process, I got cooled and solidified to become intermediary materials like slab, bloom, and billet. It’s like shaping cookie dough with cookie cutters of various shapes and sizes. Slabs are used for plates or hot rolled coil; blooms for large steel bars or wire rods; and billets are made into small steel bars or wire rods.

Step 03. Rolling process – making steel into plates or wire rods.
After casting, slab, bloom, and billet pass through several rotating rolls taking a series of constant pressure. During this process, I either get thinned out or get stretched as per the client order – in whatever thickness or length. This is the stage where I can finally become wire rods, plates, or coils.

After the rolling process was complete, I underwent yet another rounds of check-ups to see if I had all the adequate qualifications as a steel product. At this stage, I even received an identification tag! I still remember myself waiting in the storage room excited to leave for the next destination. Some of my siblings got on a ship to the United States, and some of my big siblings got transported to the port in Ulsan in a specially designed truck.

l Like Butterflies Flying All Around the World, Steel Travels and Is Everywhere

To become an adult, butterflies must undergo long and arduous journey – first fighting its way out of the eggs, and going through caterpillar and chrysalis stages. Just like butterflies, I was merely a piece of rock at birth. Then, I became sinter, then a pure ‘FE,’ then finally, steel.

My dream came true. I became advanced high-strength steel (AHSS) and got used in a car, in hydrogen batteries – also in refrigerators and washing machines! Some of me became a bridge that crosses over an ocean. I was reborn as indispensable products in people’s lives.

And I don’t just mean me in contemporary society. Even my ancestors played crucial roles in sparking Industrial Revolution and in accelerating modernization. It’s a well-known fact the Industrial Revolution kicked off right around when the steam engine started being used as the main energy source. Simultaneously, the advanced smelting technique during the eighteenth century helped replace wood railways with iron railways. Together with the steam engine, trains became another momentum pushing the Industrial Revolution forward. Even after the Industrial Revolution, I was used everywhere as construction materials, in the machinery, for ships, cars, and home electronics. I was present all throughout human history.

I go on quietly carrying out my duties whether people notice me or not. I am hiding in guitar and piano strings creating beautiful melodies – and even in ticking clocks and car tires. Have you ever noticed my presence?

Like a caterpillar who turned into beautiful butterflies, I, who was once an unpolished piece of rock is now traveling all around the world in different shapes and sizes. Look around! You will notice I’m everywhere – and right next to you, at this moment.

What are Asphalt Roads Made of?

Asphalt roads are made of a mixture of aggregates, binders and fillers. The aggregates are typically iron and/or steel slag, sand, gravel or crushed rock, and they are bound together with asphalt itself, which is a bitumen.

Asphalt comes from natural deposits, or more commonly, as a by-product of the petroleum industry. It is a prevalent material for waterproofing, caulking and preserving, and is now most frequently used for road surfaces.

The iron and steel slag used as aggregates for asphalt roads are iron and steel by-products. Steel slag is residue from the steelmaking process, made of minerals like silica, alumina and titanium from iron sand, and combinations of calcium and magnesium oxides. During the steelmaking process, slags float on top of the molten iron, forming a barrier against oxygen and maintaining the internal temperature.

In road construction, these are the preferred aggregates as they harden well, enabling a thinner layer of pavement than what can be achieved with crushed stone aggregates. Slag is also very hardy, resistant to both weather and wear.

Steel slag is a sustainable aggregate for asphalt road production. (Source: National Slag Association)

According to the Washington State Department of Transportation’s Use of Steel Slag Aggregate in Pavements report in 2015, a high iron oxide content in steel slag aggregates creates pavement that is both hard and dense, making it a superior choice over natural aggregates such as rocks in creating hot mix asphalt.

Also, when used in bituminous pavements, slag offers the advantages of high skid-resistance, stability, resistance to rutting, fatigue resistance, deformation resistance, high cohesive strength and compatibility with typical asphalt binders. Steel slag is also used as a base course material, the material under the surface layer of an asphalt road, track or surface.

The Environmental Benefits of Steel and Steel Slag

Base course material containing iron and steel slag as well as asphalt mixture containing iron and steel slag were designated as a procurement item under the Green Procurement Law. These materials are recognized as items with environmental benefits. The use of slag minimizes environmental impact as it saves energy and conserves resources.

Steelmakers need to actively find ways to reuse steel by-products to reduce their overall waste. For example, POSCO is dedicated to reusing by-products of steel making as it has a strong commitment to environmentally friendly practices. In 2016, POSCO recycled 98.4 percent of its steelworks-generated by-products, 77 percent of which was blast furnace slag and steelmaking slag.

In fact, 88 percent of POSCO’s blast furnace slag is turned into granulated blast furnace slag for cement material. POSCO carefully tests all of its steel slag products before clearing them for reuse, ensuring that every market item is suitable for its intended application.

Hot slag, or steel waste, is poured into piles to cool before being used for asphalt road construction.(Source: Fractum)

While POSCO works to improve its recycling capabilities, manufacturing and other industries are starting to see the benefits of steel and iron slag. These materials are being used everywhere, from rail ballast to artificial ocean reefs.

Steel slag is far from industrial waste, as POSCO’s efforts show. This steelmaking by-product has serious potential, now and in the future, and is a highly versatile, easily-used material for road making and other applications.

Demand for sustainable materials is on the rise in flourishing industries such as construction and manufacturing. Steelmakers like POSCO who put by-products to full use and invest in research to apply them to different industries will share the economic benefits and play a vital role towards greener business practices in the coming future.

It is also the most common material found in medical supplies that contribute to people’s health and safety on a daily basis.  

Surgical Steel

“Surgical steel” is a term used to describe stainless steels for medical applications, and are generally made up of 316, 440 and 420 stainless steels. Surgical stainless steels are corrosion resistant, have a shiny, aesthetically pleasing exterior and are extremely hygienic. Plus, they have a long life cycle and require minimal maintenance.

Surgical steel is also used for screws and joints that hold bones together. (Source: National Geographic)

Due to these properties, surgical steel is the material found in medical equipment such as syringes, scalpels and gauges. Moreover, screws used to hold broken bones together and other parts for application inside the body are made of surgical stainless steel.

For the same reasons, surgical steel is also used to make jewelry.

Know anyone who is allergic to certain types of jewelry? Often times people think they are allergic to gold or silver, but chances are, they are allergic to other alloying elements, the most common one being nickel. In the United States, up to 17 percent of women and 3 percent of men are allergic to nickel, and the number is rising. Surgical steel with zero nickel content is a safe and cost-friendly alternative, and demand for the hypoallergenic material is growing.

Surgical steel is commonly applied to piercing jewelry. (Source: Elixa)

Surgical steel was a part of the 45.8 million metric tons of stainless steel produced globally in 2016, almost double the 24.5 million metric tons produced in 2005. The growing demand and application of stainless steel are playing a positive role in the economy, but it has also been the cause of environmental pollution.

POSCO’s Surgical Steel

One of POSCO’s surgical stainless steels is the PossRB1. It is comparable to the 420J2 stainless steel that is often applied to kitchen blades, however, it has a much higher level of hardness, and thus can be applied to surgical scalpels and razor blades.

Surgical scalpels come in direct contact with the body and need to be especially clean and non-corrosive. (Source: NY Times)

Another example is POSCO’s 304i stainless steel used to make syringe needles. It is an upgraded version of 304 stainless steel with a 9 percent nickel content, traditionally applied to syringe needles. The production process of syringe needles is demanding and require multiple steps to process into the desired thinness and diameter. To add, the materials need to be especially clean, or else the needle can fracture or not reach the desired thinness. POSCO’s 304i stainless steel is manufactured using POSCO’s strip casting technology and can be processed into the thinnest diameter requirements for 32 gauge needles (dental needles).

Syringe needles require a demanding production process. (Source: Tangent Industries)

POSCO’s poStrip Technology for Stainless Steel Production

In order to reduce the harmful environmental effects of steelmaking on the environment, POSCO partnered with the Research Institute of Industrial Science & Technology (RIST) in 1989, to come up with an innovative technology for stainless steel production called poStrip, or POSCO’s strip casting technology.   

The poStrip technology is an innovative way to make steel production more sustainable. (Source: POSCO E&C)

For more than 13 years, POSCO and RIST experimented with a twin-roll strip casting system where thin strips of steel can be produced in a single, continuous process. Hot molten steel passes through two cylindrical rollers that rotate and cool the hot steel sheets immediately, thus eliminating the need for hot rolling. In conventional casting processes, molten iron is poured into molding frames to produce steel slabs that are then rolled into sheets.

The new technology vastly reduced the cost of production, delivery time as well as the amount of harmful emissions created in the steelmaking process. In the end, POSCO’s poStrip technology was perfected and applied to various types and grades of POSCO’s stainless steels.

Not only is the innovative technology cost-effective and sustainable, it produces better quality steels.

In 2015, POSCO received the Steelie Award for Innovation of the year from the World Steel Association. POSCO was recognized for its high-quality stainless steel products that were produced with the innovative strip-casting production technology. POSCO will continue to research and improve the production and overall quality of stainless steels so that its partners can manufacture world-premium supplies, machines and architecture.   

Jong-sub Lee, executive VP of POSCO (third from right) explains POSCO’s products to Young-jin Kwon, Mayor of Daegu Metropolitan City (fourth from right) and Young-doo Kim, VP of Korea Gas Corporation (second from right) at the POSCO exhibition booth.

The Asia Pacific Gas Conference is the only gas-related international conference in Korea, first held in 2015. This year, under the theme of natural gas in the future energy market, more than 100 domestic and overseas companies participated, and showcased new technologies and products.

POSCO promoted its high manganese steel, 9% nickel steel, stainless steel and POSCO E&C’s LNG Terminal design and construction technology during the event.

The exhibition space at this year’s event was divided into Product, Solution, PR and Business zones, and on display were steel products related to LNG carriers, high manganese steel LNG storage tanks and onshore LNG storage tanks. In addition, visitors were able to experience the production of POSCO GIGA STEEL and POSCO’s smart via VR videos.

The conference covered topics such as the natural gas industry’s development plans, natural gas and LNG infrastructure as well as new transportation and storage technologies. POSCO also presented a case study of high manganese steel development and production during the part of the conference focused on new material solutions for the LNG industry.

Visitors to POSCO’s exhibition booth watch VR videos about the steelmaking process and the qualities of POSCO GIGA STEEL.

POSCO was able to take away key insights on the recent and future trends of the gas industry, create new business opportunities with potential customers and expand its business with existing customers during the conference. With the new-found knowledge and partnerships, POSCO will work to find more customized and innovative solutions for its partners in the gas industry.

Cover photo courtesy of APGC 2017.

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The Steelmaking Process

So, what does a blast furnace do in the steelmaking process? There are 4 main parts to the process of making steel, and in each process, the accompanying production equipment is as vital as the materials that make steel. Each batch of steel starts off with iron, molten iron to be exact, and the blast furnace is what transforms raw materials into molten iron.

Molten iron leaves through the bottom of a blast furnace

Molten iron comes from two raw materials; iron ore and coal. First, iron ore is converted into sinter ore in a sintering plant and coal is converted into raw coke using a coke oven. The processed materials are then poured into a blast furnace through the top opening. Hot air reaching 1200℃ is blown in from the bottom through tuyeres and chemically reacts with the materials as they fall to the bottom of the blast furnace. This process oxidizes the coke and reduces the sintered ore, creating molten iron. The molten iron is then further processed to make steel.

The Importance of the Blast Furnace

The Blast furnace is one of the oldest and most significant equipment in the steelmaking process. The average lifespan of a blast furnace is about 15 years before it needs to be replaced or refurbished.

The Pohang No.1 blast furnace

POSCO is a few months shy of its 50th anniversary, and the Pohang No.1 blast furnace has been in operation for 45 of those years. Interestingly, the blast furnace has never broken down or gone out of service. With an annual capacity of 1.3 million tons, it helped establish Korea as the top-5 steelmaker in the world and was even named Korea’s Economic National Treasure No.1.

A New Technology from an Old Furnace        

In the beginning of 2017, POSCO decided to shut down the Pohang No.1 blast furnace for good in response to the slowing steel market and put the national treasure in a museum instead. It seemed the oldest operating blast furnace in Korea would finally retire.

However, just before pulling the plug, engineers used the Pohang No.1 blast furnace in a pilot operation program using low-grade raw materials such as soft coke and low-cost iron ore to produce molten iron. To everyone’s astonishment, it succeeded, and with lower charter costs than the larger blast furnaces that have 3 times the production capacity.

As it turns out, because of its smaller size, the blast furnace can operate with low-grade raw materials such as soft coke and low-cost iron ore, and can flexibly adapt to fluctuations in operations. Employees further developed the technology and as a result, Pohang No.1 blast furnace recorded the lowest charter costs of all POSCO blast furnaces in April this year.

Thanks to the new-found technology, the legacy of the Pohang No.1 blast furnace will continue.

What’s the Secret to Longevity?

Usually, a blast furnace needs to be sprayed down every 6 months so that it does not get damaged from temperatures that can reach up to 2000℃. The bottom of the blast furnace is where the heat is concentrated, thus most susceptible to damage. Furthermore, fluctuations of the internal gas composition can lead to explosions. To solve this problem, POSCO’s technicians developed a technique to lower the coke to below the tuyere and repair the bottom of the blast furnace. This technology was applied to other furnaces and maintenance systems and is still in use today.

The Pohang No.1 blast furnace’s TFT during maintenance

To add, the Pohang No.1 blast furnace even has its own voluntary task force team (TFT) to care for and maintain the blast furnace called “Love for the blast furnace, love for POSCO.” The team of 15 not only makes sure the blast furnace is operating smoothly, they also continually research new technologies to prevent malfunctions and enhance the blast furnace.          

In a matter of months, the furnace went from almost becoming an artifact to a central part of POSCO’s competitiveness. This blast furnace’s long history in itself is impressive, but with its recent transformation, there is no telling what greater innovations and technology POSCO will achieve.

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