POSCO Chairman Choi Jeong-woo. (Photos: POSCO)

POSCO has succeeded in mass producing eco-friendly graphite free-cutting steel, dubbed “PosGRAM,” or GRAphite steel for Machinability, for the first time in the world.

The graphite free-cutting steel is expected to replace lead free-cutting steel imports, for which Korea wholly depends on, thus enhancing the nation’s industrial competitiveness.

Free-cutting steel is a kind of wire rod steel cut with clean and fast machinability. It is used for producing automotive, electrical, electronic and OA equipment parts whose complex shapes and size prediction are required.

The conventional free-cutting steel contains lead to enhance machinability.

The problem is that minute particles of lead can be spread into the air in the course of producing, processing and recycling lead free-cutting steel, thus causing side-effects such as inflammation and damage to the nervous system of involved workers.

Restrictions of Hazardous Substances (ROHS) and the End of Life Vehicle (ELV), which are guidelines for limiting hazardous substances, restrict the allowable amounts of lead in products to 0.1 percent.

They make an exception in the case of the lead free-cutting steel, which has no alternative, allowing the limit amounts of lead to a maximum of 0.35 percent.

Parts, made with the world’s first eco-friendly graphite free-cutting steel, dubbed “PosGRAM (GRAphite steel for Machinability),” produced by POSCO.

Given the situation that an increasing number of global companies tend to ban the use of parts containing lead, regulations on the use of lead are expected to be reinforced.

It is noteworthy that POSCO’s development of graphite free-cutting steel has enabled it to achieve better performance in machinability by using graphite, an eco-friendly material. Through heat treatment, the graphite free-cutting steel demonstrates even surfaces in any direction of its cut, further enhancing processing efficiency.

It is also proper for precision control parts like solenoid valves as it easily magnetizes to surrounding magnetic fields. 

 In 2017, POSCO launched a project to develop the graphite free-cutting steel by securing a technology related to dispersion and control of graphite particles.

Last year, POSCO completed the development of the graphite free-cutting steel by establishing standards of mass production at a production line.

Early this year, POSCO inaugurated a companywide task force in charge of research, sales and production to secure the early settlement of the production on the market. POSCO began to sell the graphite free-cutting steel after it received favorable evaluation from clients last June.

The size of the global free-cutting steel market is estimated at 1 million tons per annum, of lwhich more than half contain lead.

There is no Korean free-cutting steel maker, so the nation has imported 23,000 tons of free-cutting steel from foreign countries, including Japan.

POSCO’s mass production of PosGRAM is expected to substitute for a great portion of imports the nation depends on.

POSCO is offering solutions for machinability conditions and tool selection tailored according to the characteristics of each client company’s facilities.

POSCO is seeking to obtain PosGRam’s certification for machine parts from Korean and foreign automakers and home appliance companies.