Abstract: The production process flowsheet of Φ180mm bars of steel 2Cr12NiMo1W1V is 80t BOF-VD-LF-ESR 6t ingot-forging-900°C annealing. The central dark zone defect which un-corresponding to GB/T1979-2001 "Standard diagram for Macrostructure and Defect of Structural Steels" occurs in macrostructure of stainless steel 2Cr12NiMo1W1V finished products. By analysis it is obtained that the normal structure of the annealed steel is ferrite matrix+carbide, while the structure in central zone is lath martensite+troostite, the corrosion resistance of troostite is poor to form dark etched zone. The original annealing process is optimized to 900℃-700°C isothermal annealing process it shall be to ensure homotransformation of structure in whole section of bar, this process can eliminate and avoid the formation of bar central dark zone of steel 2Cr12NiMo1W1V.

Key words: Stainless Steel 2Cr12NiMo1W1V, Bar Product, Macrostructure, Troostite, Annealing Process

摘要： 2Cr12NiMo1W1V钢Φ180mm棒材的生产工艺流程为80t BOF-VD-LF-ESR 6t锭-锻造-900℃退火。2Cr12NiMo1W1V不锈钢棒材成品低倍组织中出现GB/T1979-2001《结构钢低倍组织缺陷评级图》中无对应类型的中心黑色腐蚀区域缺陷,分析得出,该钢退火后的正常组织为铁素体基体+碳化物,而中心区域为板条马氏体+托氏体,托氏体耐腐蚀性差,形成黑色区域。将原先的退火工艺优化为900℃-700℃等温退火工艺,可保证全截面组织的均匀转变。该工艺可消除和避免2Cr12NiMo1W1V钢棒材中心黑色区域。

关键词: 2Cr12NiMo1W1V不锈钢, 棒材, 低倍组织, 托氏体, 退火工艺