不锈钢316LN中厚板超低温冲击功偏低原因分析及优化建议  

Cause analysis and optimization suggestion on low impact energy for stainless steel 316LN at ultra-low temperature

作　　者：陈旭[1] 宋红梅[1] CHEN Xu;SONG Hongmei(Research Institute,Baoshan Iron & Steel Co. ,Ltd. , Shanghai 201999, China)

机构地区：[1]宝山钢铁股份有限公司中央研究院,上海201999

出　　处：《宝钢技术》2021年第1期60-64,共5页Baosteel Technology

摘　　要：利用金相、扫描电镜能谱分析和电子背散射衍射(EBSD)等分析手段对试验用钢316LN超低温冲击功偏低的原因进行了分析。结果表明,试验用钢316LN中心层析出的块状σ脆性相是低温冲击功偏低的主要原因。通过Thermo-calc相图理论分析计算,钢板中心层的σ脆性相是铸坯心部高温δ铁素体在后续的变形,及热处理过程中700~950℃停留较长时间析出的。采用合适的热加工工艺可避免高温δ铁素体及σ相的析出,从而提高材料超低温冲击韧性。The detailed reasons for low impact energy of stainless steel 316LN were investigated by using optical microscope,EDS and EBSD techniques.Results indicated that the massiveσphase with brittle property precipitated from the center layer of 316LN was the main reason for relatively low impact energy in the experiment.According to the calculation from Thermo-calc software,theσphase within the center layer was precipitated from theδferrite following hot deformation and annealing at 700-950℃for a long time.However,theδferrite andσphase can be eliminated with proper Thermo-mechanical treatments,in order to improve the impact properties under ultra-low temperature.

关 键 词：316LN不锈钢 冲击韧性 Σ相 Δ铁素体 

分 类 号：TG142.71[金属学及工艺—金属材料]