奥氏体化温度对9Cr-1Mo-V-Nb钢组织与性能的影响

Effect of Austenitizing Temperature on Structure and Mechanical Properties of 9Cr-1Mo-V-Nb Steel

研究了不同奥氏体化温度加热后 9Cr 1Mo V Nb(ASMESA 2 13T91)钢正火和正火 +回火后的组织和力学性能 ,应用电子显微镜和X ray衍射分析了钢的组织形态和萃取试样的碳化物分布。结果表明在 980～ 112 0℃加热正火后 ,T91钢均得到板条马氏体组织 ,但马氏体板条束的大小显著不同。奥氏体加热温度对T91钢的奥氏体晶粒大小和室温性能有明显影响。10 6 0℃以下 ,钢的性能随加热温度增加而提高 ,在 10 70℃出现转折 ,超过该温度性能变化不大。影响钢的性能的因素主要与合金元素的固溶和奥氏体晶粒长大有关。

The microstructure and mechanical properties of 9Cr 1Mo V Nb(ASME SA 213 T91) steel after normalizing and normalizing & tempering heated under different austenitizing temperature were studied in the paper.The microstructure and carbides distribution on the electrolytic extraction samples were analyzed by means of SEM,X ray diffraction.It established that the lath martensite is obtained through normalizing under the different austenitizing temperature within 980 to 1120℃,but the size of martensite lath is obviously different.The properties and austenite size of the steel is markedly influenced by the austenitizing temperature.The properties of the steel increases with the heating temperature below 1060℃.However,the properties of the steel decrease critically at 1070℃ and be come stable beyond 1070℃.The properties are influenced by solution of alloy elements and austenite grain size.It is suggested that the heating temperature of the steel should be taken under 1060℃ in order to avoid the abnormal large austenite grain formed at about 1070℃.The effect mechanism of carbides content and its distribution on the property,austenite formation and grain growth was discussed.