9Cr18不锈钢半固态控温冷却显微组织特征  

MICROSTRUCTURE CHARACTERISTICS OF 9Cr18 STAINLESS STEEL SEMI-SOLID TEMPERATURE-CONTROLLED COOLING

作　　者：裴中正 Pei Zhongzheng(Technology Research Department of CRRC Industrial Research Institute Co.,Ltd.,Beijing 100070)

机构地区：[1]中车工业研究院有限公司技术研究部,北京100070

出　　处：《河北冶金》2023年第1期35-38,共4页Hebei Metallurgy

摘　　要：利用Gleeble3800热模拟试验机研究了不同冷却速率和不同保温温度条件下9Cr18不锈钢半固态控温冷却显微组织特征及硬度变化规律。结果表明:经不同速率由半固态冷却至室温后,显微组织仍存在固相区和液相区,固相和液相区域的显微硬度都较为稳定,固相显微硬度处于310~345 HV之间,液相显微硬度处于435~480 HV之间。不同冷却速率条件下固相区并未发生马氏体相变,为高温冷却下来的奥氏体组织。试样经1050℃和800℃保温固相区域显微组织中出现马氏体组织,主要是由于在1050℃和800℃保温过程中固相区域合金元素分布状态降低了奥氏体的稳定性,在保温后继续冷却过程中出现了奥氏体组织向马氏体组织的转变,导致试样的显微硬度有所上升。而550℃和200℃保温温度已低于原奥氏体化温度,因此在后续转变过程中奥氏体仍较为稳定,最终固相区域仍为奥氏体组织。The microstructure and hardness of 9Cr18 stainless steel were studied by Gleeble3800 thermal simulation testing machine under different cooling rates and different holding temperatures.The results show that after cooling from semi-solid to room temperature at different rates,the microstructure still exists in the solid phase and the liquid phase,and the microhardness of the solid phase and the liquid phase is stable.The microhardness of the solid phase is between 310~345 HV,and that of the liquid phase is between 435~480 HV.There is no martensitic phase transition in the solid phase at different cooling rates,and it is austenitic structure cooled down at high temperature.The sample was held at 1050℃ and 800℃ and martensitic structure appeared in the regional microstructure,mainly because the distribution of alloy-elements in the solid phase during the process of holding at 1050℃ and 800℃ reduced the stability of austenite,and the transformation from austenitic structure to martensitic structure occurred in the process of continued cooling after holding.The microhardness of the sample increases.However,the temperature of 550℃ and 200℃ is lower than the original austenitizing temperature,so the austenite is still relatively stable in the subsequent transformation process,and the final solid phase region is still austenitic structure.

关 键 词：9Cr18不锈钢 半固态 冷却速率 保温温度 马氏体 硬度 

分 类 号：TG142.1[一般工业技术—材料科学与工程]