300M钢表面喷丸强化工艺应用研究

目的 对比和研究300 M钢的铸钢丸和陶瓷丸喷丸强化后的效果,选择合适的300 M钢喷丸强化工艺.方法 采用铸钢弹丸和陶瓷弹丸以不同喷丸强度对300 M钢表面进行喷丸强化,研究对300M钢表面粗糙度、表面残余压应力及疲劳寿命的影响.结果 随着喷丸强度的增大,300 M钢表面粗糙度增大,但在相同或相当的喷丸强度下,采用陶瓷弹丸喷丸强化可获得更小的表面粗糙度;试样表面残余压应力均为先增大后减小,分别在喷丸强度为0.25A和0.2A时达到最大值.在大应力水平试验条件下,两种弹丸不同喷丸强度下的300M钢中值疲劳寿命增益均不明显;在小应力水平试验条件下,两种弹丸不同喷丸强度下的300 M钢中值疲劳寿命增益差异显著,铸钢弹丸喷丸强化最大值达到22,陶瓷弹丸喷丸强化最大值达到38.结论 铸钢丸和陶瓷丸喷丸均可以提高300 M钢的疲劳寿命.相对于铸钢丸喷丸,300M钢的陶瓷丸喷丸后的粗糙度水平更低,疲劳寿命更长.

Application Research of Shot Peening Process on 300M Steel Surface

Objective To compare and study the performance results of 300M steel after ceramic shot and cast steel shot peening and obtain the proper shot peening process of 300M steel. Methods 300M steel was shot peened by cast steel shot and ceramic shot at different intensities. The surface roughness, surface residual stress and fatigue life of 300M steel shot peened by two different shot methods were tested and researched. Results The surface roughness of 300M increased after shot peening by both ceramic shot and cast steel shot, but lower roughness value was achieved by ceramic shot peening under the same condition of shot peening intensity. The surface residual compressed stress first increased and then decreased with the increase of shot peening intensity by ceramic shot peening or cast steel shot peening. When the cast steel shot peening intensity was 0. 25A, the residual stress of the surface reached the maximum. For ceramic shot peening, the residual stress of the surface reached the maximum when the intensity was 0. 2A. Under the condition of large stress level test, the median fatigue life gain of the sample with different shot peening intensity of two kinds of shot was not obvious. However, under low stress level test conditions, median fatigue life gain was significantly different with different shot peening intensity of two kinds of shot, with the maximum value reaching 22 (steel shot peening) and 38 (ceramic shot peening), respectively. Conclusion The fatigue life could be increased by both cast steel shot peening and ceramic shot peening, but the 300M steel processed by ceramic shot peening had lower roughness level and longer fatigue life.