磨削工艺对渗碳M50NiL钢表面变质层微观结构和性能及疲劳性能影响  

GRINDING PROCESS EFFECT ON SURFACE MODIFICATIVE LAYER MICROSTRUCTURE,PROPERTY AND FATIGUE BEHAVIOR OF CARBURIZED M50NiL STEEL

作　　者：罗庆洪[1] 李春志[1] 娄艳芝[1] 赵振业[1] 

机构地区：[1]北京航空材料研究院,北京100095

出　　处：《金属学报》2012年第2期194-198,共5页Acta Metallurgica Sinica

摘　　要：本文以渗碳热处理后的M50NiL钢为研究对象,利用Vickers硬度计、XRD,TEM,HRTEM以及旋转弯曲疲劳试验仪对普通磨削和精密磨削后试样表面变质层微观结构和硬度及试样的疲劳性能进行了研究.结果表明:进刀量不同的2种磨削工艺获得的试样表面粗糙度不同,表面变质层微观结构和硬度以及试样疲劳性能差别较大.精密磨削对试样硬度产生影响的深度较小.普通磨削表面变质层奥氏体含量较多,呈现明显的奥氏体"有效晶粒"现象;精密磨削表面变质层则为非常细小的变形马氏体组织,呈现明显的纳米级马氏体"有效晶粒"现象;"有效晶粒"之间无明显的界面,且晶面扭转现象明显,相邻"有效晶粒"之间转动角度最大可达14°,同时"有效晶粒"内部晶面也存在轻微扭转现象;精密磨削工艺试样的旋转弯曲疲劳寿命约为普通磨削的13倍.The surface hardness field,modificative layer microstructure and fatigue properties of carburized M50NiL steel after ordinary grinding and precision grinding,were studied using Vickers hardness tester,XRD,TEM,HRTEM and the rotating bending fatigue tester.The results showed that two grinding processes are different only on the amount of feed and surface roughness,but bring larger changes in the surface hardness field,modificative layer microstructure and fatigue properties.Two kinds of grinding have different effects on the hardness depth,the impact depth of precision grinding is smaller;There was more austenite on ordinary grinding surface,and the surface layer showed a clear modificative layer of austenitic ＂effective grain＂;precision grinding surface modificative layer is very small deformation nano-martensite,but also shows a clear ＂effective grain＂ phenomenon;＂effective grain＂ no obvious interface;＂effective grain＂ turning phenomenon is apparent,adjacent ＂effective grain＂ rotation angle is up to 14°,while,there are slight turning phenomenon within the ＂effective grain＂;rotating bending fatigue life of precision grinding increases by about 13 times of ordinary grinding sample.

关 键 词：M50NiL钢 磨削变质层 显微硬度 微观组织 疲劳性能 

分 类 号：TG115.21[金属学及工艺—物理冶金]