多元低合金耐磨铸钢热处理过程中的碳化物析出行为  

Carbide precipitation behavior of multiple low-alloyed and wear-resistant cast steel during heat treatment

作　　者：刘腾轼 杨弋涛[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200072

出　　处：《金属热处理》2015年第9期33-39,共7页Heat Treatment of Metals

摘　　要：借助OM、SEM、TEM、EDS和JMat Pro模拟软件研究和分析了正火及正火后回火低合金铸钢试样中碳化物的析出行为及碳化物析出对试样组织和性能的影响。结果表明,Mo、Nb等合金元素的加入使珠光体转变C曲线右移,正火后试样由铸态粗大的铁素体和珠光体转变为铁素体和贝氏体铁素体组织,晶内有少量含Nb碳化物析出。试样890℃正火后500-650℃内回火,回火后试样组织转变为粒状珠光体和铁素体,560-590℃回火试样具有较优的综合力学性能;回火后试样的晶界处有少量合金碳化物析出,晶内有大量细小弥散的含Nb碳化物析出。Effects of different normalizing and tempering temperatures on carbides precipitate,microstructure and properties of low-alloyed cast steel were investigated by using OM,SEM,TEM,EDS and JMat Pro simulation software. The results show that adding Mo and Nb alloying elements makes the pearlite transformation C curve move to the right. After normalizing,coarse ferrite and pearlite of as-cast steel transform into ferrite and bainite ferrite,and a small amount of Nb carbides are precipitated inside of the grain. Normalized at 890 ℃ and tempered within 500-650 ℃,microstructure of the samples transform into granular pearlite and ferrite,and the specimens have optimum mechanical properties when tempered within 560-590 ℃. After tempering,a small amount of alloy carbides are precipitated along the grain boundaries,and a large number of fine dispersed Nb carbides are precipitated inside of the grain.

关 键 词：多元低合金铸钢 正火 回火 碳化物析出 组织性能 

分 类 号：TG142.13[一般工业技术—材料科学与工程]