JFE Steel Launches High Strength Steel Bar for Automobile

JFE Steel announced on Monday that the firm established the world first technology to make 2-3 micrometers of fine steel crystal structure stably and commercialized ultra high strength steel bar with ultra fine austenite structure or gamma structure, Fine gamma. The firm succeeded to improve the fatigue strength by 15-30% from traditional S53C grade heat treated steel by making ultra fine steel structure. The firm said the new steel could reduce car weight by around 45 kilogram per unit by downsizing power train parts including crankshaft. Some automakers already started the test. JFE Steel tries to expand the automobile steel bar business with the new products. The steel bar with fine steel structure has 50% better fatigue strength than nitrocarburizing heat treated steel. With the new steel, the weight of crankshaft, constant velocity universal joint and transmission shaft decreases by 10-20% reducing the vehicle weight and carbon dioxide emission. JFE Steel produces wire rod and steel bar at the West Japan Works’ Kurashiki area with 35,000 tonnes of monthly output capacity and the subsidiary, JFE Bars and Shapes’ Sendai plant with 70,000 tonnes of capacity. The firm produces 3,000 tonnes of the new steel bar at Kurashiki at first to expand the automotive steel bar business though the Sendai plant can make the product. The firm tries to expand the profitability by improving products mix with such only-one and number-one products. Making of fine steel structure is basically technology to make finer ferrite structure. The strength of the new steel bar is as much as 2,500 megapascal while traditional technology to make steel with fine structure is applied to flat steel with up to 800 MPa of strength. JFE Steel tries to apply the product for construction and industrial machinery and to apply the technology for plate and other type of steel products.