GH4169高温合金车削表面完整性对疲劳性能的影响

发布时间：2018-02-04 20:56

本文关键词： GH合金表面应力集中系数残余应力显微硬度疲劳寿命　出处：《航空材料学报》2017年06期 　论文类型：期刊论文

【摘要】：通过车削和旋转弯曲疲劳实验,研究直接时效态GH4169高温合金车削进给量对表面完整性的影响,以及表面完整性对疲劳寿命的影响。结果表明:当进给量f从0.2 mm/r减小到0.02 mm/r时,表面粗糙度R_a从1.497μm减小到0.431μm;表面残余应力从拉应力状态逐渐转变为压应力状态;表面塑性变形层从8μm减小到2μm左右;表面应力集中系数是GH4169疲劳寿命的主要影响因素,随着表面应力集中系数增大,疲劳寿命显著下降;在实验参数范围内,当f=0.13 mm/r时,可获得好的表面完整性,表面应力集中系数K_(st)为1.166,表面显微硬度为405.27HV_(0.025),表面残余应力为82.08 MPa,获得的平均疲劳寿命为6.98×10~4周次;车削表面疲劳断口具有多源疲劳断裂特征,疲劳源起始于试件加工表面的缺陷处。
[Abstract]:The effect of turning feed on surface integrity of direct aging GH4169 superalloy was studied by turning and rotating bending fatigue experiments. And the effect of surface integrity on fatigue life. The results show that when feed f is reduced from 0. 2 mm/r to 0. 02 mm/r. The surface roughness R _ a decreases from 1.497 渭 m to 0.431 渭 m; The surface residual stress changed from tensile stress state to compressive stress state. The plastic deformation layer is reduced from 8 渭 m to 2 渭 m. The surface stress concentration factor is the main factor affecting the fatigue life of GH4169. With the increase of the surface stress concentration factor, the fatigue life decreases significantly. In the range of experimental parameters, good surface integrity can be obtained when fen is 0. 13 mm/r, and the surface stress concentration factor (KS) is 1. 166. The surface microhardness is 405.27 HVS 0.025, the surface residual stress is 82.08 MPa, and the average fatigue life is 6.98 脳 10 ~ (4) weeks. The fatigue fracture of the turning surface is characterized by multi-source fatigue fracture, and the fatigue source originates from the defect of the specimen surface.
【作者单位】：西北工业大学现代设计与集成制造技术教育部重点实验室;
【基金】：973项目资助
【分类号】：TG132.3;TG51
【正文快照】： GH4169高温合金(国外牌号为Inconel 718)是以fcc奥氏体为基,以γ″-Ni3Nb为主要强化相,并辅以γ'-Ni3(Al,Ti,Nb)强化的镍基高温合金[1]。GH4169高温合金具有优异的高温强度、抗氧化、抗蠕变、抗腐蚀能力和良好的疲劳特性。尤其在650℃高温下,其力学性能具有很好的稳定性,能够

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