热处理对Fe-5Cr-1.4B合金组织和性能的影响  

Influence of Heat Treatment on Structure and Property of Fe-5Cr-1.4B Alloy

作　　者：顾建[1] 符寒光[1] 雷永平[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100022

出　　处：《现代铸铁》2013年第4期78-84,共7页Modern Cast Iron

摘　　要：研究了不同热处理工艺对Fe-Cr-B合金显微组织和性能的影响。试验结果表明:Fe-Cr-B合金的凝固组织主要由Fe2B、M(7C,B)(3M=Fe,Cr)、α-Fe及γ-Fe组成,共晶组织呈网状分布。经过淬火处理后,呈网状结构的硼化物发生断裂,基体转变为马氏体,并伴有二次碳硼化物M2(3C,B)6析出。当淬火加热温度超过1 050℃,二次碳硼化物析出相的数量减少,宏观硬度和显微硬度随温度的升高而增加,在1 050℃时,达到最大值,超过1 050℃时,硬度略有下降。经过回火处理后,马氏体发生回火软化,基体中继续析出细小二次碳硼化物,硬度相对淬火态下略有下降,并随着回火温度的升高,下降趋势增加,在500℃回火时冲击韧度达到最高值,为7.35 J/cm2。The influences of different heat treatment processes on the microstructure and properties of Fe-5Cr-1.4B alloy were investigated.The experiment result indicated that the solidified structure of Fe-Cr-B alloy was consisted mainly of Fe2B,M（7C,B）3,（M=Fe,Cr）,α-Fe and γ-Fe,and its eutectic structure exhibited netlike distribution.After quenching treatment,netlike boride ruptured and matrix transformed into martensite which was accompanied by the separation of secondary boride M2（3C,B）6.When the quenching temperature was higher than 1 050 ℃,the separating phase quantity of the secondary boride reduced,macrohardness and microhardness increased with temperature enhancing and reached maximum value at 1 050 ℃.When temperature was higher than 1 050 ℃,the hardness decreased appreciably.After tempering treatment,the tempering softening of martensite took place,the separation of fine secondary carbide-boride from matrix continued,the hardness decreased appreciably compared with as-quenched hardness and the decreasing tendency increased with enhancing of tempering temperature,and when tempering at 500 ℃,the impact toughness reached its maximum value of 3.75 J/cm2.

关 键 词：FE-CR-B合金 淬火 回火 显微组织 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]