热处理工艺对含镁新型热挤压模具性能的影响  

Influence of heat treatment process on the properties of new-typed hot-extruded die containing magnesium

作　　者：赵平[1] 关云卿[1] 赵国际[1,2] 

机构地区：[1]重庆工业职业技术学院机械工程学院,重庆401120 [2]重庆大学材料科学与工程学院,重庆400044

出　　处：《锻压技术》2016年第10期138-141,共4页Forging & Stamping Technology

基　　金：重庆市教委科研项目(KJ132105);2010年重庆市高等教育教学改革重大项目(101403)

摘　　要：为了研究热处理工艺对4Cr5Mo Si V1Mg1含镁新型热挤压模具的耐磨损性能和抗热疲劳性能的影响,选用6种不同的工艺对含镁新型热挤压模具进行热处理,并对热处理后的模具分别进行表面硬度测试、500℃高温摩擦磨损试验及热疲劳试验。结果发现:当退火温度从820℃提高到920℃或淬火温度从1000℃提高到1080℃时,模具的表面硬度、耐磨损性能和抗热疲劳性能均先升高后下降;与870℃×8 h常规退火相比,采用870℃×2 h+700℃×6 h等温退火可以使模具的表面硬度增加14%、500℃磨损体积减小45%、网状裂纹级别从2级减小至1级、主裂纹级别从2级减小至1级、热疲劳裂纹级别从4级减小至2级。因此,含镁新型热挤压模具的退火工艺优选为870℃×2 h+700℃×6 h等温退火,淬火温度优选为1040℃。In order to study the influences of heat treatment process on the wear resistance and thermal fatigue resistance of the new-typed hot-extruded die containing magnesium 4Cr5 Mo Si V1Mg1,the new-typed hot-extruded dies were heated under six different processes,and the surface hardness test,high temperature wear test at the temperature of 500 ℃ and thermal fatigue test of the dies after heat treatment were conducted and analyzed. The results show that they first increase and then decrease with increase of annealing temperature from820 ℃ to 920 ℃ or quenching temperature from 1000 ℃ to 1080 ℃. Comparing with normal annealing 870 ℃ × 8 h,the isothermal annealing 870 ℃ × 2 h ＋ 700 ℃ × 6 h increases the surface hardness by 14%,decreases wear volume by 45% at 500 ℃,reduces the mesh crackle and main crackle grade from grade 2 to grade 1 respectively,and reduces the grade of thermal fatigue crackle from grade 4 to grade2. Thus,the optimized annealing process is the isothermal annealing process at 870 ℃ × 2 h ＋ 700 ℃ × 6 h,and the optimized quenching temperature is 1040 ℃.

关 键 词：热挤压 模具 等温退火 淬火 磨损 热疲劳 

分 类 号：TG162.4[金属学及工艺—热处理]