85Cr18Mo2V钢质进气门断裂失效分析及预防措施  

Analysis and prevention measures of failure fracture for 85Cr18Mo2V steel intake valve

作　　者：姚玲珍[1] 陈文[1] 邓益中[1] 李其新 倪洪义[1] 王媛妮[2] 

机构地区：[1]湖南天雁机械有限责任公司,湖南衡阳421005 [2]南华大学机械工程学院,湖南衡阳421001

出　　处：《锻压技术》2014年第5期6-8,12,共4页Forging & Stamping Technology

基　　金：湖南省衡阳市科技局重点资助项目(2013KJ03)

摘　　要：针对85Cr18Mo2V钢质进气门产生的失效断口,进行裂纹形貌观察和显微组织分析,结合生产实际进行工艺试验,找出裂纹产生的原因和形成机理,并提出有效的预防改进措施。试验表明,该种气门失效的主要原因与断裂处组织存在严重的网状碳化物有关,而严重网状碳化物的形成则与气门顶锻成形时的温度紧密相关。通过合理调节毛坯顶锻成形时的各种工艺参数如次级电压、加热时间等来调控温度,可有效避免或减少严重网状碳化物的产生,最终避免或减少气门盘部和颈部断裂现象的产生。The crack morphology was observed and the microstrueture was analyzed for the failure fracture produced by 85CrlSMo2V steel intake door. Combined with actual production, the process test was conducted, the cause and formation mechanism of the crack were found, and the effective prevention and improvement measures were put forward. Experiments show that the main reasons of failure for valve are related to the serious network carbide in fracture tissue, and the forming of the network carbide is closely related by the tempera- ture of valve upsetting. Through reasonable adjusting the parameters to control temperature when blank upsetting, such as secondary volt- age, heating time, etc. , the serious carbide network can be effectively avoided or reduced, which resulting in avoiding or reducing frac- ture for valve plate and neck.

关 键 词：85Cr18Mo2V钢 进气门 疲劳断裂 锻造成形 网状碳化物 

分 类 号：TG316[金属学及工艺—金属压力加工]