DZ125定向凝固合金的喷丸工艺  

Shot peening process of directionally solidified DZ125 alloy

作　　者：王欣 杨清 于鹏 马世成 Wang Xin;Yang Qing;Yu Peng;Ma Shicheng(Surface Engineering Institution,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Aviation Key Laboratory of Advanced Corrosion and Protection on Aviation Materials,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Disk and Shaft Machining Branch,AECC Shenyang Liming Aero-engine Co.,Ltd.,Shenyang Liaoning 110043,China)

机构地区：[1]中国航发北京航空材料研究院表面工程研究所,北京100095 [2]中国航发北京航空材料研究院航空材料先进腐蚀与防护重点实验室,北京100095 [3]中国航发沈阳黎明航空发动机有限公司盘轴加工分厂,辽宁沈阳110043

出　　处：《金属热处理》2021年第1期149-153,共5页Heat Treatment of Metals

摘　　要：针对DZ125合金开展铸钢丸喷丸强化研究,分析了多种喷丸强度、覆盖率条件下合金700℃旋弯疲劳性能、表面残余应力和硬度梯度。结果表明:随喷丸强度的增大,中值疲劳寿命估计量逐渐增大,高喷丸强度时,700℃/500 MPa中值疲劳寿命估计量是原始试样的2倍;随表面覆盖率的增大,中值疲劳寿命估计量呈现先增大后稳定的趋势,当覆盖率达到400%时,中值疲劳寿命估计量达到稳定;高喷丸强度且表面覆盖率达到400%时疲劳极限为480 MPa,较原始试样疲劳极限(400 MPa)提高20%。残余应力和组织强化机制是DZ125合金喷丸的强化因素,随着喷丸强度的增大,残余压应力数值略有减小,但均明显大于原始状态;高喷丸强度时,覆盖率400%时DZ125合金表面产生超过200μm深度的硬度场,且表面硬度较基体(430 HV0.1)提高37%。当缺口部位实际载荷大于屈服强度时,疲劳过程中残余应力和硬度都将明显松弛,经历700℃/600 MPa/1.5×10^(5)周次的断裂试样,表面残余应力降低54%,表面硬度下降14%。Cast-steel shot peening was employed on directionally solidified alloy DZ125 to analyze the fatigue property,surface residual stress and microhardness profile under various shot peening intensity and coverage conditions.The results show that with the increase of shot peening intensity,the estimated median fatigue life increases gradually.At high intensity,the estimated median fatigue life at 700℃/500 MPa is2 times that of the original specimen.Moreover,with the increase of surface coverage,the estimated median fatigue life increases first and then stabilizes,and when the coverage reaches 400%,the estimated median fatigue life is stable.When the shot peening intensity is high and at the coverage rate of 400%,the fatigue limit is 480 MPa,which is 20% higher than the original value(400 MPa).Residual stress and microstructure strengthening mechanism are the strengthening factors of shot peening for DZ125 alloy.With the increase of shot peening intensity,the residual compressive stress decreases slightly,but it is still obviously larger than the original state.When the shot peening intensity is high and at the coverage rate of 400%,the surface hardness field of DZ125 alloy exceeds 200μm in depth,and the surface hardness is 37% higher than that of the matrix(430 HV0.1).When the actual load at the notch is greater than the yield strength,the residual stress and hardness are relaxed obviously during fatigue process;the surface residual stress of the fractured specimen decreases by 54% and the surface hardness decreases by 14% after 700℃/600 MPa/1.5×10^(5) cycles.

关 键 词：DZ125合金 喷丸强度 表面覆盖率 疲劳 应力松弛 

分 类 号：TG668[金属学及工艺—金属切削加工及机床] V263.5[航空宇航科学与技术—航空宇航制造工程]