| 摘要: |
| 利用圆磨、一次喷丸和二次喷丸3种不同的加工方法，在C250型超高强度钢（C250钢）上引入不同的表面完整性状态。研究了不同表面完整性状态下C250钢试样的表面形貌、表面粗糙度和表面残余应力等表面完整性参数并分析了其在室温下的光滑（应力集中系数，Kt=1）旋转弯曲疲劳SN曲线和缺口（Kt=1.7）旋转弯曲疲劳SN曲线。结果表明：由于表面完整性状态的优化，相比圆磨状态，一次喷丸后C250钢光滑试样和缺口试样的疲劳极限分别提高15.4%和18.1%，二次喷丸后分别提高26.2%和20.1%，在C250钢疲劳性能方面二次喷丸增益更大。然而，二次喷丸后C250钢的缺口敏感性较一次喷丸有所增大，原因是二次喷丸带来的表面平滑化和最大残余压应力外移效果对光滑试样疲劳性能影响明显，但对缺口试样影响相对较小。 |
| 关键词: 表面完整性 超高强度钢 喷丸 疲劳极限 缺口敏感性 |
| DOI：10.3969/j.issn.1007-9289.2014.02.012 |
| 分类号: |
| 基金项目: |
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| Effect of Surface Integrity on the High Cycle Fatigue Property of C250 Ultra-high Strength Steel |
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WANG Xin, TENG Baiqiu, ZENG Huiyuan, JIANG Zhihua, TANG Zhihui1,2,3
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1a. Laboratory of Number Five, 1b. Laboratory of Number Three, Beijing Institute of Aeronautical Material, Beijing 100095;2. General Technical Research Center, Shenyang Aeroengine Research Institute, Shenyang 110015;3. Research Center, Xi′an Aeroengine (group) Ltd., Xi′an 710021
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| Abstract: |
| Different surface integrity conditions were induced on C250 ultrahigh strength steel, by different surface finishing methods, including circle grinding, single shot peening and double shot peening. The surface topography, surface roughness and residual stress profile and rotatingbending fatigue SN curves with smooth specimens (stress concentration coefficiency, Kt=1) and notch specimens (Kt=1.7) at room temperature were investigated. The results indicate that, compared with circle grinding, the fatigue limit of smooth and notch specimens after single shot peening increases 15.4% and 18.7%, respectively; the fatigue limit after double shot peening increases 26.2% and 20.1%, respectively, because of the optimization of surface integrity by peening. It means that double shot peening is more significant in extending the fatigue lives of C250 steel. However, the fatigue notch sensitivity of C250 steel after double shot peening is higher than that of single shot peening, because surface smoothing and movingoutside of residual stress peak, using double shot peening have more influence on the fatigue property of smooth specimens than that of notch specimens. |
| Key words: surface integrity superhigh strength steel shot peening fatigue limit fatigue notch sensitivity |
