P92钢回火组织与韧性研究
Investigation on tempered microstructure and toughness of P92
李新梅，张忠文，杜宝帅，彭宪友
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作者单位：山东电力研究院
中文关键字：超超临界机组 P92钢 正火和回火 组织和韧性 回火脆性
英文关键字：ultra supercritical unit; P92 steel; normalizing and tempering; microstructure and toughness; tempering brittleness
中文摘要：利用金相显微镜、扫描电镜和X-射线衍射仪并通过冲击试验研究了P92钢经1050℃正火+不同回火温度后的微观组织和韧性变化。结果表明：正火后P92钢组织为典型的板条马氏体，并有一定量的残余奥氏体和M23C6析出相存在。回火后随温度变化P92钢的组织和冲击功均发生了一定变化，回火温度较低时，P92钢的组织形态和冲击功变化不大，在500℃-600℃温度范围出现了马氏体板条碎化、大部分或全部残余奥氏体分解和一定的回火脆性；而后随着回火温度升高组织中亚结构数量增多并出现块状铁素体，而冲击功则快速升高。
英文摘要：Microstructure and toughness of P92 steel treated with different tempering temperature after being normalized at 1050 oC was studied by optical microscopy, scanning electron microscopy, X-ray diffractometer and impact test. Results show that normalized P92 steel consists of typical martensite lath, remaining austenite and M23C6 precipitates. It is found that with the changing of tempering temperature microstructure and impact energy of P92 steel varied accordingly. Microstructure and toughness changed slightly at relatively lower tempering temperature. The phenomena of martensite lath breaking, dissociation of remaining austenite and tempering brittleness were found between 500 and 600 oC. With the increase of tempering temperature the amount of sub-structure increased and blocky ferrite was also observed, resulting in the rapid increase of impact energy.