Last year, California experienced the worst wildfires to date. (Source: Live Science)

It wasn’t just wildfires. The fire that broke out in Grenfell Tower in West London last June claimed 71 lives and sparked a public outcry for stricter building regulations around fire safety. The material used as cladding to wrap the outer part of the building came under scrutiny as it was extremely flammable and contributed to the rapid spread of the flames.

To prevent further disasters, architects, builders and policymakers need to reexamine the materials that go into building people’s homes, workplaces and public facilities.

Materials Matter

Steel is one of the most popular materials for construction as it is 100 percent recyclable, cost-effective and easy to work with. Moreover, World Steel Association’s Steel Construction Fact Sheet shows that steel is the most-researched and best-understood construction material available today. Its inherent characteristics and widely-available reinforcement options make steel the safest construction material for fire resistance.

eel is one of the strongest construction materials under high heat. (Source: CIC)

Fire resistance refers to the duration of time a building can withstand the load of the building, limit the passage of flames and gases and insulate the building against rising temperatures during a fire.

Steel is considered to be a fire-resistant material because it can retain all of its strength in temperatures up to 370ºC (700ºF). At 500ºC (930ºF), it loses 30 percent of its strength and at temperatures above 538ºC (1000ºF), unprotected steel loses close to half of its strength.

To put things into perspective, aluminum starts to decrease in strength when temperatures rise above 100ºC (212ºF), and at 204ºC (400ºF), aluminum loses 60 percent of its strength. Copper also loses 25 percent of its strength at 204ºC (400ºF).

Putting Materials to the Test

Darchem Engineering conducted the first-ever fire-resistance test in 1990 comparing galvanized steel, stainless steel, aluminum and fiberglass. Each material was exposed to temperatures from 1000 to 1050ºC (1832 to 1922ºF) for a period of 5 minutes. Both types of steel passed with minimal damage, while aluminum collapsed after 26 seconds, and fiberglass collapsed almost immediately.

Fire-resistance tests show that stainless steel is one of the most fire-resistant materials available. (Source: Applus)

They also conducted a 2-hour test with the same materials exposed to temperatures from 552 to 555ºC (1026 to 1032ºF). For stainless steel, the testing time was extended to 3 hours and it still had the least amount of damage out of all the materials. Galvanized steel passed the 2-hour mark, but did produce some molten zinc. Aluminum failed after 12 minutes, while fiberglass gave out in 6 minutes.

The results showed that steel, especially stainless steel, is the most fire-resistant material. However, one can never be safe enough when it comes to fire safety, and there are several ways to increase the fire resistance of steel that fall into 3 major categories.

Passive Fire Protection

Passive fire protection methods include boards, sprays and films that insulate the steel surface or structure against high temperatures. Fire protection boards are the most common type of passive fire protection as they can be customized and designed to fit the interior of the building. However, they are quite labor-intensive and costly compared to other options.

Boards are the most common types of passive fire protection. (Source: IPCOM)

Active Fire Protection

Active fire protection refers to any automatic or manual measure that can be taken to detect or fight fires. These include water sprinkler systems, alarms, smoke detectors, first responders and more. With advancements in AI and smart sensors, active fire protection will see vast improvements in the years to come and software systems will likely play a great role in fire prevention and protection.

The majority of active fire protection measures will become automated. (Source: Frontier Fire)

Intumescent fire protection

Intumescent fire protection includes paint-like substances that swell up in high temperatures and act as insulation against the heat. Typically, the intumescent substance will become 50 times thicker than its original state at about 200-250°C, well before steel undergoes any structural damage. Recently, intumescent paints have become much more prominent than passive types of fire protection as they are cost-effective, and can be applied on and off-site saving builders time and money.

Most recently, scientists and engineers from Nanyang Technological University (NTU) and national industrial developer JTC Corporation came up with a new intumescent fire protection paint called Firoshield. It is much cheaper than other types of intumescent paint and takes half the time to apply. The innovation will allow steel buildings to maintain its structural integrity for 2 hours with only 5 layers of paint, compared to the 15 layers required by other paints. 

Such innovations are expected to reinforce the safety of steel buildings, giving people more time for evacuation and limiting the spread of smoke and flames. On a final note, the fire-resistant qualities of steel should be taken into consideration not only for building frames and exteriors, but also for staircases, doors and other parts of a building that must stay intact for safe evacuations as well as for the safety of first responders.

Here’s a look at how steel is produced in a steel mill or factory, and what the “smartization” of steel factories will look like.

So, how is steel made?

Iron Making

To make steel, manufacturers first need molten iron. Molten iron comes from two raw materials; iron ore and coal. 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 poured into a blast furnace where hot air reaching 1200℃ is blown in from the bottom through tuyeres, causing a chemical reaction. This process oxidizes the coke and reduces the sintered ore, creating molten iron.   

Steelmaking

In the steelmaking stage, the molten iron is transported to the steel making plant via a torpedo car, where the liquid is poured into a converter. Then, oxygen is blown into the converter to burn off all the impurities. All that is left is pure molten steel.

Continuous Casting

This is where steel finally becomes solidified into different shapes such as slab, bloom and billet. Liquid steel is poured into molds and cooled as it passes through a continuous casting machine until it solidifies into the desired shape.

Hot steel passes through rolling machines to be rolled into specific sizes and thicknesses. (Source: Global Sourcing Blog)

Rolling Process

During the rolling process, steel is heated once more to achieve various sizes and thicknesses. Steel slabs are heated to over 1100℃, then pass through rolling machines. This results in hot-rolled coils that can be shaped for different uses such as thick plates. They can also be processed into long, wire-shaped rods for billets. Often, the hot-rolled coils are rolled at room temperature for cold-rolled coils. Cold-rolled coils can be fabricated to produce galvanized and electrical steel products.

“Smartizating” these processes will involve converging IoT, Big Data, and AI to connect the different facilities, IT systems and workers in order to collect and analyze data for optimization.

POSCO is “smartizing” the steel-production process

POSCO is a steel company looking to lead the industry in adopting smart factories. CEO Kwon Ohjoon made “smartization” one of the 4 key priorities for POSCO starting back in 2014, and Kwon will continue to increase those investments.

POSCO smart factory incorporates artificial intelligence to enhance safety and efficiency.

SEE ALSO: How Smart Factories are Changing the Manufacturing Industry

In 2016, POSCO established its Smart Solution Council in order to research AI, big data and IoT applications. In the same year, POSCO ICT’s smart factory platform, PosFrame, was completed and installed in POSCO’s Gwangyang Steel Mill. PosFrame allows engineers to collect and monitor big data. So far, the company has saved over USD 14 million by incorporating the new technology in its production practices.

Here are some other features of POSCO’s Smart Factory.

POSCO’s Smart Blast Furnace

The Pohang Blast Furnace No.3 became a smart furnace in 2017, following a 102-day repair period. The furnace is now equipped with automated sensors that monitor and control its internal conditions using AI technology. Smart sensors monitor the blast furnace for factors like raw material quality and ventilator status, preventing breakdowns and ensuring a much longer lifecycle.

SEE ALSO: Will Artificial Intelligence Lead to Breakthroughs in the Steel Industry?

Worker Safety

Smart sensors can be used for more than just process monitoring. The company is working toward a full implementation of smart sensors for safety purposes, using IoT to create a better working environment.

Steel manufacturing involves high temperatures and high pressure levels, which is dangerous for workers who come in close contact with the equipment. With smart sensors monitoring all of the factory information, workers will instead be monitoring operation from a safe distance.

Workers in POSCO’s smart factory wear smart sensors for safety.

Wearable sensors, in conjunction with factory smart sensors, will be able to detect if and when workers are approaching potentially dangerous areas, and will alert them. These sensors will also detect and alert with regards to any impending accidents, or life-threatening situations like gas leaks, explosions, or fires.

Also, dust, sulfur, and nitrogen compounds will be removed via a high-plasma method, creating an eco-friendly steel plant and a healthier environment for workers.

POSCO will continue to add more smart features to its steel mills to increase efficiency, safety and sustainability. In efforts to learn and implement new technologies, POSCO CEO Kwon Ohjoon visited GE’s smart factories to learn about their technology earlier this year. POSCO also held the 2017 Smart POSCO Forum to share its insights with clients and affiliates, all as part of its expanding smartization efforts.