EFFECF OF PREFERENTIAL HEAT TREATMENT ON MICROSTRUCTURE OF NEW MARTENSITIC HEAT RESISTANT STEEL G115
Intermediate heat treatment and thermo-mechanical treatment are the two possible ways of preferential heat treatment.Microstructure of G115 martensitic heat resistant steel after traditional heat treatment and preferential heat treatment was tested by field emission scanning electron microscope(FESEM)and electron back-scattered diffraction(EBSD).The results show that intermediate heat treatment can hardly change the size of precipitates while the precipitates can be obviously refined after thermo-mechanical treatment.Additionally,there is no obvious difference in precipitate size after deforming at different thermo-mechanical treatment temperatures.The reason why intermediate heat treatment failed in G115 steel can be attributed to that the content of Nb is low and most of V is in solution.The reason for the success of thermo-mechanical treatment is that after thermo-mechanical treatment but without tempering,the amount of large angle boundaries has a three-fold increase compared with that after traditional heat treatment.Since M23C6 particles are mainly precipitated along large angle boundaries,the increase of large angle boundaries can induce the increase of the precipitation site of M23C6 particles,resulting in the refinement of M23C6 particles.After deforming at different temperatures,the amount of large angle boundaries is close,so the size of M23C6 is nearly the same.
G115 martensitic heat resistant steel intermediate heat treatment thermo-mechanical treatment refinement precipitate
Peng Yan Zhengdong Liu Yuqing Weng
Technology Center for Tube Pipe and Bar,BaoShan Iron and Steel Co.,Ltd,Shanghai 201999,China Institute for Special Steels,China Iron and Steel Research Institute,Beijing 100081,China
国际会议
Energy Materials 2014(第一届能源材料国际会议)
西安
英文
137-143
2014-11-04（万方平台首次上网日期，不代表论文的发表时间）