喷丸工艺对1Cr11Ni2W2MoV钢螺母表面性能和显微组织的影响

Effect of Shot Peening Process on Surface Properties and Microstructure of 1Cr11Ni2W2MoV Steel Nut

采用3种不同喷丸强化工艺(干喷丸、先干喷丸后湿喷丸以及湿喷丸)对1Cr11Ni2W2MoV钢螺母表面进行强化处理,比较了喷丸工艺对螺母表面残余应力、粗糙度、显微组织的影响。结果表明:湿喷丸后螺母表面残余压应力最大,且最大残余压应力出现在大圆弧截面处,达到550 MPa,同时表面粗糙度R_(a)最小,分布在0.75~0.85μm范围;干喷丸后螺母的表面残余压应力最小,表面粗糙度R_(a)最大,分布在2.5~3.2μm范围。喷丸后螺母外层晶粒破碎而得到明显细化,而中心层的晶粒未发生明显变化;湿喷丸工艺和先干喷丸后湿喷丸工艺分别在螺母表面形成0.15,0.25 mm深度的残余应力层,适合采用先干喷丸后湿喷丸方式对1Cr11Ni2W2MoV钢螺母表面进行强化处理。

Three different shot peening processes(dry shot peening,dry shot peening followed by wet shot peening and wet shot peening)were used to strengthen the surface of 1 Cr11 Ni2 W2 MoV steel nut.The effects of shot peening process on the residual stress,roughness and microstructure of nut surface were compared.The results show that the residual compressive stress on the nut surface after wet shot peening was the largest,and the maximum residual compressive stress located at the large arc section,reaching 550 MPa;the surface roughness R_(a) was the smallest with the range of 0.75-0.85μm.After dry shot peening,the surface residual compressive stress of nut was the smallest,and the surface roughness R_(a )was the largest ranging from 2.5-3.2μm.After shot peening,the outer grains of nut was broken and refined obviously,while the grains of the center did not change obviously.After wet shot peening and dry shot peening followed by wet shot peening,0.15 and 0.25 mm depth residual stress layers were formed on nut surface,respectively.The suitable process for strengthening the surface of 1 Cr11 Ni2 W2 MoV steel nut was dry shot peening followed by wet shot peening.