循环载荷下喷丸层残余应力与半高宽的变化

Changes of Residual Stress and Full Width at Half Maximum in Shot Peening Strengthened Layer under the Cycle Load

为研究30Cr Mn Si A钢喷丸强化层抗疲劳性能在受循环载荷作用过程中的变化情况,采用疲劳试验机对30Cr Mn Si A喷丸试样施加循环载荷,通过X射线残余应力测试仪测量试样表面残余应力和X射线衍射半高宽等数据,研究其在循环载荷作用下的变化规律。结果表明:喷丸引入的残余压应力在平行于载荷方向上早期即发生大幅松弛,之后基本保持稳定不变;松弛幅度随载荷的增加而增加,垂直载荷方向上的残余压应力基本不松弛;各个方向上的半高宽都会随循环次数的增加而下降,下降规律基本与应力松弛规律相同,载荷越大,半高宽下降越多。

To research the change of anti-fatigue performance under the cycle load for the shot peening strengthened layer of 30 Cr Mn Si A steel,the fatigue machine are used to apply cycle load to 30 Cr Mn Si A shot peening specimens and X-ray residual stress tester are also used to measure the surface residual stress of specimen and full width at half maximum of X-ray diffraction. The result of study shows that the residual compressive stress which is induced by shot peening and in parallel with the direction of cyclic loading loosed sharply in the early time. The degree of stress relaxation increased with increasing load while rare relaxation is observed on the direction perpendicular to the force. With the increasing of cycle times,the full width at half maximum is declining in any direction. The regulation of the decrease of full width at half maximum is similar to the residual compressive stress relaxation. And the full width at half maximum reduces more when the load is increasing.