喷丸强化对H13钢表面完整性的影响

为研究不同强度喷丸对H13钢表面完整性的影响,采用白光干涉仪、显微硬度计、XRD、SEM和EBSD等对喷丸前后H13钢试样的表面粗糙度、硬度、残余应力和表层微观组织等表面完整性进行了表征,并定量分析了未喷丸和经0.33A喷丸的试样表层组织的晶粒尺寸、晶界取向差及织构等的变化规律。结果表明,不同强度喷丸均改变了H13钢的表面完整性。喷丸在提高表面粗糙度和塑性硬化程度的同时引入了具有一定深度的残余压应力层。与未喷丸试样相比,经0.23 A喷丸后H13钢表面粗糙度提高了约152%。随着喷丸强度从0.23 A增大到0.33 A,硬化层深度由100μm增至160μm,残余压应力层深度由200μm增至300μm。H13钢的未喷丸组织的平均晶粒尺寸为950 nm,晶界平均取向差为33.5858°,主要存在强度较弱的{001}100和{110}111型混合织构;经0.33 A喷丸后距表面10μm处的平均晶粒细化至470 nm,晶界平均取向差增至39.0228°,组织中出现了两类{111}uvw和{hkl}110型板织构,且表层晶粒细化层深度达30μm以上。

Influence of shot peening on surface integrity of steel H13

To study the influence of shot peening on the surface integrity of steel H13 under different intensities, the surface roughness, hard-ness, residual stress and surface microstructure of specimen were investigated by white-light interferometer, microhardness tester, XRD, SEM and EBSD, and the grain size, grain boundary misorientation and texture of surface layer before and after 0. 33 A shot peening were analyzed quantitatively. The results show that the surface integrity of steel H13 are all changed after shot peening under different intensities, and the shot peening can improve the surface roughness and microhardness, and induce the residual compressive stress layer with a certain depth at the same time. Therefore, comparing with the specimen without shot peening, the surface roughness of steel H13 is increased by 152% after 0. 23 A shot peening, and the depth of hardening layer is increased from 100μm to 160μm as well as the depth of residual compressive stress layer increased from 200μm to 300μm with the shot peening intensity increasing from 0. 23 A to 0. 33 A. However, for none shot peened specimen, the average grain size is 950 nm, and the average grain boundary misorientation is 33. 5858° due to {001} <100> and {110} <111> mixed textures with weak strength existing in the specimen. Furthermore, after 0. 33 A shot peening, there are two kinds of {111} < uvw > and{hkl}<110> plate textures in the microstructure at the region 10μm away from the surface with a depth of grain refinement layer more than 30 μm, and the average grain size is refined to 470 nm, and the average grain boundary misorientation increases to 39. 0228°.