Comparison of Quality between C70S6 Steels Produced by Chinese and Oversesa Steelmakers for Fracture Splitting Connection Rod

Cracking technology requires materials with advanced performances of high strength,low toughness,well-cutting and small plastic deformation during brittle fracture.The C70 S6 steel is an important material for fracture splitting connection rod.The steels produced by Chinese and overseas steelmakers had been compared in terms of their comprehensive performance.The samples of Chinese steel have higher sulfur and manganese content,while nickel,vanadium,titanium content are lower. All samples have same microscopic structures comprising lamellar pearlite and small amount of ferrite.However,overseas samples have smaller grain size and lower ferrite amount.Besides,for overseas samples,the sulfide is in form of spindle and distributes evenly in matrix,and amount of complex inclusions is higher. For Chinese samples,the sulfide in long-strip state distributes uniformly and the amount of complex inclusions is smaller.