405不锈钢高温组织转变研究  

Study of microstructure evolution for 405 stainless steel under high temperature

作　　者：胡锦程[1] 宋红梅[1] 

机构地区：[1]宝山钢铁股份有限公司研究院,上海200431

出　　处：《宝钢技术》2015年第4期62-67,72,共7页Baosteel Technology

摘　　要：通过热膨胀法以及Thermo—Calc热力学计算软件对SA240—405不锈钢铁素体向奥氏体转变的温度进行了测量和计算。进一步结合淬火与回火热处理，分析了405不锈钢在高温下组织随温度与时间的变化关系。研究结果表明，405不锈钢铁素体向奥氏体开始转变的温度为795～832℃，转变终了温度为910-925℃。温度高于1050℃，随温度升高，奥氏体逐渐向铁素体转变，淬火后的马氏体含量降低。在950及980℃淬火，得到的组织为马氏体与铁素体的双相组织，淬火时间为30～60min得到的硬度较高；进一步延长淬火时间，硬度逐渐降低。在730℃回火后得到的组织为铁素体与回火马氏体，无明显残余奥氏体，回火后组织的硬度随时间延长逐渐降低。The phase transformation temperature of ferrite to austenite for SA240 -405 stainless steel was measured by applying thermodiatometry method and calculated using the Thermo-Calc software. Meanwhile, the effect of temperature and soaking time on the microstructure evaluation was studied by different quenching and tempering treatment. The results demonstrated that the transformation of the ferrite to austenite of this steel started between 795 - 832 ℃, and finished during 910-925 ℃. When the specimens annealed at temperature higher than 1 050℃, austenite would transform into ferrite gradually, consequently the content of as-quenched martensite decreased with the increasing temperature. Moreover, when the specimens quenched between 950 ℃ and 980 ℃, the microstructure of duplex phases composed of ferrite and martensite was obtained. The relatively high HRB values could be obtained when the quenching time was kept for 30 -60 minutes, and then the hardness would gradually decrease with increasing quenching time. Tempering at 730 ℃ resulted in ferrite and tempered martensite, and no obvious residual austenite was observed. Meanwhile the hardness gradually decreased with the increasing tempering time .

关 键 词：405不锈钢 组织变化 相变 

分 类 号：TG142.71[一般工业技术—材料科学与工程]