工程科学学报，第39卷，第5期：731-738.2017年5月 Chinese Journal of Engineering,Vol.39,No.5:731-738,May 2017 D0I:10.13374/j.issn2095-9389.2017.05.011;htp://journals.ustb.edu.cn 20 CrMnTi齿轮钢的点蚀敏感性及裂纹萌生风险 余稳)，向嵩12)四，石维12)，马国强)，于明飞) 1)贵州大学材料与冶金学院，贵阳5500252)贵州省材料结构与强度重点实验室，贵阳550025 区通信作者，E-mail:xiangs.221@163.com 摘要利用弱腐蚀倾向的溶液环境，控制20 CrMnTi钢产生有限的亚稳态蚀点分布.运用电化学噪声法，研究了20 CrMnTi 钢亚稳态蚀点的萌生规律，结合ANSYS有限元计算，导人真实腐蚀形貌，对比研究了不同腐蚀条件下蚀孔周边的应力分布与 裂纹萌生风险.结果表明，20CMT具有较高的点蚀敏感性，其亚稳态蚀点集中在杂质相边缘优先形核，随Cˉ浓度的升高， 点蚀孕育期明显缩短，点蚀敏感性增大.不同CI~浓度下引起的形核速率上升会缩短蚀点间距，表面微裂纹易连接蚀点而发 生扩展，增大裂纹萌生风险 关键词齿轮钢；点蚀；电化学噪声：有限元模拟 分类号TG172.9 Pitting sensitivity and crack initiation risk of 20CrMnTi gear steel YU Wen),XIANG Song),SHI Wei2),MA Guo-giang),YU Ming-fei) 1)College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China 2)Guizhou Material Structure and Strength Key Laboratory,Guiyang 550025,China Corresponding author,E-mail:xiangs221@163.com ABSTRACT An environment with a weak corrosion tendency was used to promote the production of a limited metastable pitting distribution in 20CrMnTi steel.The law of metastable pitting initiation was investigated by using electrochemical noise.Using the ANSYS finite element method,the stress distribution and crack initiation risk of holes were analyzed and compared under different corrosion conditions.The results indicate that the pitting sensitivity of 20CrMnTi steel is high.The initiation of metastable pitting is preferentially concentrated at the edge of the impurity phase.The pitting induction period is obviously shortened and the pitting sensi- tivity increases with an increase in the Cl"concentration.The increase in the nucleation rate induced by different Cl"concentrations reduces the distance between pitting occurrences.Thus,surface microcracks readily connect and propagate pitting,thereby enhancing the risk of crack initiation. KEY WORDS gear steel;pitting;electrochemical noise;finite element simulation 齿轮是传递动力的关键基础件，据统计四，除过载钢，在闭式齿轮箱中，受较高的润滑油电阻率保护，齿 导致的断齿外，在正常运行载荷下，52.5%的齿轮失效面不可能发生大面积的宏观腐蚀.但由于20CMTi 是由于齿面疲劳导致的齿根位置疲劳断裂引起的，而属于中低碳钢，耐蚀性较差，随齿轮箱长时间服役，容 齿面疲劳形式主要包括齿面点蚀和剥落.20 CrMnTi由 易出现箱体密封失效，引入水蒸气、盐雾等侵蚀性介 于其良好的淬透性与高强度常被作为齿轮与轴承用 质，导致润滑油劣化、乳化而腐蚀齿面.同时，部分润 收稿日期：2016-08-04 基金项目：国家自然科学基金资助项目(51361004,51661006)：贵州省百层次创新型人才资助项目(20164014)：贵州省科技计划资助项目 (20142003,20147603,20152031)；贵州省教育厅创新群体重大研究资助项目(2016021)：贵州大学人才基金资助项目(201448)工程科学学报,第 39 卷,第 5 期:731鄄鄄738,2017 年 5 月 Chinese Journal of Engineering, Vol. 39, No. 5: 731鄄鄄738, May 2017 DOI: 10. 13374 / j. issn2095鄄鄄9389. 2017. 05. 011; http: / / journals. ustb. edu. cn 20CrMnTi 齿轮钢的点蚀敏感性及裂纹萌生风险 余 稳1) , 向 嵩1,2) 苣 , 石 维1,2) , 马国强1) , 于明飞1) 1) 贵州大学材料与冶金学院, 贵阳 550025 2) 贵州省材料结构与强度重点实验室, 贵阳 550025 苣 通信作者,E鄄mail:xiangs221@ 163. com 摘 要 利用弱腐蚀倾向的溶液环境,控制 20CrMnTi 钢产生有限的亚稳态蚀点分布. 运用电化学噪声法,研究了 20CrMnTi 钢亚稳态蚀点的萌生规律,结合 ANSYS 有限元计算,导入真实腐蚀形貌,对比研究了不同腐蚀条件下蚀孔周边的应力分布与 裂纹萌生风险. 结果表明,20CrMnTi 具有较高的点蚀敏感性,其亚稳态蚀点集中在杂质相边缘优先形核,随 Cl - 浓度的升高, 点蚀孕育期明显缩短,点蚀敏感性增大. 不同 Cl - 浓度下引起的形核速率上升会缩短蚀点间距,表面微裂纹易连接蚀点而发 生扩展,增大裂纹萌生风险. 关键词 齿轮钢; 点蚀; 电化学噪声; 有限元模拟 分类号 TG172郾 9 Pitting sensitivity and crack initiation risk of 20CrMnTi gear steel YU Wen 1) , XIANG Song 1,2) 苣 , SHI Wei 1,2) , MA Guo鄄qiang 1) , YU Ming鄄fei 1) 1) College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China 2) Guizhou Material Structure and Strength Key Laboratory, Guiyang 550025, China 苣 Corresponding author, E鄄mail: xiangs221@ 163. com ABSTRACT An environment with a weak corrosion tendency was used to promote the production of a limited metastable pitting distribution in 20CrMnTi steel. The law of metastable pitting initiation was investigated by using electrochemical noise. Using the ANSYS finite element method, the stress distribution and crack initiation risk of holes were analyzed and compared under different corrosion conditions. The results indicate that the pitting sensitivity of 20CrMnTi steel is high. The initiation of metastable pitting is preferentially concentrated at the edge of the impurity phase. The pitting induction period is obviously shortened and the pitting sensi鄄 tivity increases with an increase in the Cl - concentration. The increase in the nucleation rate induced by different Cl - concentrations reduces the distance between pitting occurrences. Thus, surface microcracks readily connect and propagate pitting, thereby enhancing the risk of crack initiation. KEY WORDS gear steel; pitting; electrochemical noise; finite element simulation 收稿日期: 2016鄄鄄08鄄鄄04 基金项目: 国家自然科学基金资助项目(51361004, 51661006); 贵州省百层次创新型人才资助项目(20164014); 贵州省科技计划资助项目 (20142003,20147603,20152031); 贵州省教育厅创新群体重大研究资助项目(2016021); 贵州大学人才基金资助项目(201448) 齿轮是传递动力的关键基础件,据统计[1] ,除过载 导致的断齿外,在正常运行载荷下,52郾 5% 的齿轮失效 是由于齿面疲劳导致的齿根位置疲劳断裂引起的,而 齿面疲劳形式主要包括齿面点蚀和剥落. 20CrMnTi 由 于其良好的淬透性与高强度常被作为齿轮与轴承用 钢,在闭式齿轮箱中,受较高的润滑油电阻率保护,齿 面不可能发生大面积的宏观腐蚀. 但由于 20CrMnTi 属于中低碳钢,耐蚀性较差,随齿轮箱长时间服役,容 易出现箱体密封失效,引入水蒸气、盐雾等侵蚀性介 质,导致润滑油劣化、乳化而腐蚀齿面. 同时,部分润