l POSCO develops eco-friendly free-cutting steel ‘PosGRAM’
l PosGRAM features enhanced machinability and is harmless to human body compared to lead free-cutting steel
l POSCO provides cutting solutions customized for each client
POSCO (CEO Jeong-Woo Choi) succeeded in developing and mass-producing eco-friendly graphite free-cutting steel named PosGRAM (GRAphitic steel for Machinability) for the first time in the world and has set to expand sales.
POSCO’s PosGRAM is expected to enhance the national industrial competitiveness, as it is to replace lead free-cutting steel, which was entirely reliant on imports.
Free-cutting steel is a kind of wire rod product that is specially designed to be machined by chip removal with high productivity. It is mainly used for fabricating parts for automotive and electronic & OA equipment, where complex shapes and size precision are required.
The existing free-cutting steel contained lead to improve machinability. However, during the production, processing, and recycling stages of the products, the lead is dispersed into the air as fine particles of micrometer size (µm), thus causing various side effects, such as inflammation and damages to the nervous system of workers.
Due to these concerns, RoHS and ELV, which are international guidelines for restricting hazardous substances, has limited the amount of lead in products to 0.1%. However, in the case of lead free-cutting steel, which has no alternative, the standards allow up to 0.35%. Considering that the ban of lead-containing parts is proliferating among global companies, guidelines to regulate the overall use of lead is also expected to intensify.
*Restrictions of Hazardous Substances (ROHS): A directive of the EU limiting hazardous substances in electrical and electronic products
*ELV (End of Life Vehicle): A directive of the EU addressing the end of life for automotive products.
POSCO’s development of the graphite free-cutting steel, PosGRAM, is significant in that it has successfully achieved better performance in machinability than lead free-cutting steel utilizing graphite, an eco-friendly material. Through heat treatment, PosGRAM displays even surfaces in any direction of its cut, enabling efficient processing. It is also suitable for fabricating precision control parts like solenoid valves as it easily magnetizes to surrounding magnetic fields.
*Solenoid valve: A valve that works by moving a plunger (an iron rod) with the electromagnetic force generated by passing electricity through a solenoid (an electric coil), which is wound in a cylindrical shape. Free-cutting steel is used here as a material for a plunger.
In 2017, POSCO set to develop free-cutting steel, starting with the research of the distribution and control technology of graphite particles. Completing development and establishing standards for its mass production last year, POSCO formed a company-wide task force that would be in charge of research, sales, and production earlier this year to settle the product promptly in the market. Since receiving favorable evaluation from clients last June, POSCO has started full-fledged production.
The global market for free-cutting steel is estimated at 1 million tons a year, of which more than half contain lead. There is no domestic lead free-cutting steel manufacturer in Korea, so over 23,000 tons are imported annually from overseas. The mass production of PosGRAM is expected to offer an alternative to the imported lead free-cutting steel.
To expand the sales of PosGRAM, POSCO is providing solutions for machinability condition and tool selection according to the features of each customer’s facilities. POSCO is also pursuing to obtain PosGRAM’s certification for machine parts from domestic and overseas automotive and home appliance companies.
▲ Machine parts made with POSCO’s eco-friendly graphite free-cutting steel, PosGRAM