| 摘要 |
PURPOSE: An austenitic stainless steel for cold forming suitable for later machining exhibiting improved mechanical properties over standard austenitic stainless steels in which these properties are very valuable for cold working applications, particularly cold heading is provided. CONSTITUTION: The austenitic stainless steel for cold working suitable for later machining has a composition by weight comprising carbon<0.030%, 0.3%<silicon<1%, 5%<manganese<9%, 4.55%<nickel<7%, 15%<chromium<18%, molybdenum<0.8%, 2%<copper<4%, 0.02%<nitrogen<0.060%, sulfur<0.01% and phosphorus<0.030%, wherein the composition also comprises 50x10¬-4% of boron, wherein the Md30 index, defined by the formula: Md30=551-462(C%+N%)-9.2Si%-20Mn%-13.7Cr%-29Ni%-29Cu%-18.5Mo%, is -60 or less, and wherein the ferrite rate after reheating of the raw solidification structure to 1,240 deg.C. is 10% or less, as per the following formula: % Ferrite=0.034x¬2+0.284x-0.347, where x=6.903 £Creq-Nieq/1.029-6.998|, with Creq=Cr% and Nieq=Ni%+20.04C%+21.31N%+0.46Cu%+0.08Mn%.
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