正火温度对含硅型高铬马氏体耐热钢性能的影响  

Effect of Normalizing Temperature on Mechanical Properties of a Si-bearing High Chromium Martensitic Heat Resistant Steel

作　　者：周强国[1,2] 石全强[1,2] 严伟[1] 王威[1] 单以银[1] 杨柯[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]中国科学院大学,北京100049

出　　处：《材料研究学报》2013年第5期461-468,共8页Chinese Journal of Materials Research

基　　金：中国科学院战略性先导科技专项子课题(XDA03010301;XDA03010300);国际热核聚变实验堆(ITER)计划专项课题(2009GB109002);中国科学院知识创新工程(KJCX2-YX-N35)资助项目~~

摘　　要：以一种硅和碳量分别为1.5%和0.32%的含硅型高铬马氏体耐热钢为对象,研究了正火温度对其组织和力学性能的影响。结果表明,实验钢中的大量碳化物在980℃以上正火时溶解,热膨胀曲线上发生额外膨胀现象,回火后沿板条界析出杆状和粒状两种形态碳化物;在1030-1100℃正火并回火后沿晶界析出的含硅Cr23C6碳化物易粗化,呈链状分布于晶界;正火温度低于1030℃时拉伸强度随着温度的提高而提高,在更高温度下正火基本保持不变;随着正火温度的提高,冲击韧性总体呈降低趋势,分布在晶界的大尺寸链状含硅碳化物弱化晶界是冲击韧性快速降低的主要原因。Effect of normalizing temperature on the microstructure and mechanical properties of a martensitic heat resistant steel with high contents of silicon, chromium and carbon was investigated. It was found that carbides in the steel dissolved greatly above 980℃, additional expansion occurred on the thermal dilation curve and two forms of Cr23C6 were decorated along the lath boundaries after tempering. When normalized at 1030-1100℃, large size Cr23C6 carbides containing silicon precipitated along the grain boundaries. Tensile properties of the steel increased with normalizing temperature below 1030℃ and kept almost unchanged at higher normalizing temperatures. The toughness of the steel decreased with normalizing temperature and the large size chain-like Cr23C6 carbides along grain boundaries were the key factor to reduce the toughness.

关 键 词：金属材料 马氏体耐热钢 正火温度 组织与性能 晶界碳化物 

分 类 号：TG142[一般工业技术—材料科学与工程]