ISSN:1003-8620

CN:42-1243/TF

主管:中信泰富特钢集团股份有限公司

主办:大冶特殊钢有限公司

特殊钢 ›› 2017, Vol. 38 ›› Issue (5): 10-12.

• 试验研究 • 上一篇    下一篇

800℃至500℃冷却时间对9Ni低温钢相转变行为和微观结构的影响

杨秀芝,华文林,杨春杰,董春法   

  1. 湖北理工学院机电学院,黄石 435003
  • 收稿日期:2017-04-19 出版日期:2017-10-01 发布日期:2022-07-08
  • 作者简介:杨秀芝(1974-),女,博士(2006年武汉科技大学),副教授, 1993年武汉汽车工业大学(本科)毕业,焊接新材料和工艺研究。
  • 基金资助:
    湖北省教育厅青年基金(Q20123001);
    湖北省自然科学基金(2014CFB177);
    校级重大项目(2015A05)资助;

Effect of Cooling Time from 800℃ to 500℃ on Phase Transition Behavior and Microstructure of Low Temperature Steel 9Ni

Yang Xiuzhi , Hua Wenlin , Yang Chunjie , Dong Chunfa   

  1. Mechanical and Electrical Engineering College, Hubei Science and Technology Institute, Huangshi 435003
  • Received:2017-04-19 Published:2017-10-01 Online:2022-07-08
  • Supported by:
    Youth Fund of Hubei Education Department (Q20123001) ;
    Hubei Nature and Science Foundation (2014CFB177) ;
    Major school-level projects (2015A05) ;

摘要: 利用Gleeble-3500热模拟试验机对9Ni低温钢(/%:0.049C,0.22Si,0.58Mn,0.0006S,0.0029P,9.16Ni,0.020Al,0.003Ti,0.0030N,0.0009O)在800℃冷却至500℃时间-t8/5(6~100s)的热循环过程进行了模拟,结合金相法建立了试验钢的SHCCT(模拟热影响区连续冷却转变)曲线。采用光学显微镜和扫描电镜对不同t8/5试样的显微组织进行了观察,研究了冷却时间对原奥氏体晶粒尺寸、M-A组元含量、尺寸、数量和形状因子(M-A组元面密度)的影响。结果表明,模拟热影响区连续冷却试样的显微组织由贝氏体(B)和马氏体(M)组成,其相对含量取决于冷却时间t8/5;随800℃至500℃(t8/5)冷却时间的增加原奥氏体晶粒尺寸,粒状贝氏体含量、M-A组元尺寸增加,同时M-A组元含量和面密度降低,有利于改进9Ni钢粗晶热影响区的低温韧性。

关键词: 热模拟影响区连续冷却转变(SHCCT), 9Ni低温钢, 800℃-500°C相变, M-A组元, 贝氏体

Abstract: The simulation on circulation process of heat of low temperature steel 9Ni (/% : 0.049C, 0.22Si, 0.58Mn, 0.0006S, 0.0029P, 9.16Ni, 0.020Al, 0.003Ti, 0.0030N, 0.0006O) with different cooling time (6-100 s) from 800 °C cooling to 500 ℃(t8/5) has been carried out by using Gleeble-3500 simulator, and combined with metallography the simulated heat affected zone continuous cooling transformation (SHCCT) curves of tested steel are established. The structure in tested specimen with different cooling time of t8/5 is observed by optical and scanning electron microscope to study the effect of cooling time on original austenite grain size, M-A group area, size, number and shape factor (ratio of massive M-A). Results show that the structure of simulated heat affected zone of continuous cooling specimen consists of bainite (B) and martensite (M) , the relative content of M depends on cooling time of t8/5 ; with increasing cooling time from 800 °C to 500℃ (t8/5 ) the original austenite grain size, particle bainite content and M-A group size increase while the M-A group content and ratio of massive M-A decrease, it is available to improve the low temperature toughness of coarse grain heat affected zone of steel 9Ni.

Key words: Simulated Heat Affected Zone Continuous Cooling Transformation ( SHCCT), Low Temperature Steel 9Ni, Phase Transition from 800°C to 500°C, M-A Group, Bainite