发动机高温螺栓紧固可靠性研究

赵振龙^1,2，孙丹^1,2，崔海冰^1,2

1.内燃机可靠性国家重点实验室，山东潍坊261061； 2.潍柴动力股份有限公司, 山东潍坊261061

摘要：针对高温工作环境下螺栓轴力衰减问题，理论分析螺栓轴力衰减的原因；通过试验研究和分析螺栓工作温度、材料性能变化、高温蠕变、热膨胀等对高温螺栓的轴力衰减规律。研究表明：高温下材料机械性能下降、蠕变增加是导致高温螺栓轴力衰减的主要因素，材料、温度、载荷等影响高温蠕变速率，温度越高、载荷越大，蠕变速率越快，螺栓紧固件材料设计选择、连接结构优化、降低工作温度等可提高高温螺栓的可靠性。

关键词：高温螺栓；高温蠕变；热膨胀

Reliability research on engine high temperature bolt fastening

ZHAO Zhenlong^1,2，SUN Dan^1,2，CUI Haibing^1,2

1.State Key Laboratory of Internal Combustion Engine Reliability，Weifang 261061，China； 2.Weichai Power Co., Ltd., Weifang 261061，China

Abstract：Aiming at the problem of axial force attenuation under the working condition of high-temperature bolts, the axial force attenuation law of high-temperature bolts is studied and analyzed from the aspects of bolt working temperature detection, material property change, high-temperature creep, thermal expansion and so on. The results show that the decrease of mechanical properties, high temperature creep and thermal expansion are the main factors leading to the attenuation of axial force of high temperature fasteners. The factors affecting the high temperature creep rate are material, temperature and load. The higher the temperature and load, the faster the creep rate. High temperature fastening connection design must be carried out from the aspects of fastener material design and selection, connection structure optimization and working temperature reduction, so as to improve the reliability of high temperature bolts.

Keywords:high temperature bolt; high temperature creep; thermal expansion