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Deformed steel bar/Low alloy high strength steel

wageni  chanzo: tarehe:2014-5-16 17:23:54

Deformed steel bar/A brief history of high strength low alloy steels in the 1940s to develop. /Deformed steel bar Factory/The earliest American steel with AISI4340 and 4130 by lowering the tempering temperature, the tensile strength of steel up to 1600 ~ 1900MPa, used in the manufacture of aircraft landing gear and other important structural components , to reduce aircraft weight and achieved significant results . /Hot Rolled Coils/Early 1950s, in order to further improve the strength of steel and improve the toughness of steel, steel on the basis of AISI4340 1.5% silicon and 0.1% vanadium and the successful development of 300M steel , tempering temperature increased from 200 ℃ to 300 ℃, the tensile strength up to 1860 ~ 2060MPa, ductility and toughness of steel were significantly improved . 1960s successfully developed D6AC steel mainly used for manufacturing a variety of models of solid fuel rocket motor casing , a tensile strength of 1600MPa. Mid-1970s , the United States Steel Corporation on the basis of the Republican 4340M steel on the silicon content up to 2.5% up to 0.20% vanadium developed a high purity HP310 steel, tensile strength of 2135MPa, while the transverse section shrinkage of large cross-section bar still maintained at above 25%. Meanwhile, other countries to develop low- alloy high strength steel has 911,643 former Soviet Union , France 35NCI) 16 , etc. have been used in the manufacture of aircraft structural components , the tensile strength of steel at 1900MPa more. Since the 1990s, the development of ultra-high strength low alloy steels mainly uses new techniques and new technology to improve the purity of steel, changing the shape and distribution of inclusions study ultrafine grain size , stable tensile strength steel 1700 ~ 2000MPa, the fracture toughness increased to 85MN more.