某型柴油机主轴承盖螺柱断裂分析及其制造工艺改进  

Fracture Analysisand Manufacturing Process Improvement of Main Bearing Cover Stud of a Diesel Engine

作　　者：程德彬 薛记恩 郝波 郝敬 CHENG Debin;XUE Jien;HAO Bo;HAO Jing(Military Representative Office of Navy,Luoyang 471039,China;Henan Diesel Engine Heavy Industry Co.,Ltd.,Luoyang 471039,China)

机构地区：[1]海军驻洛阳地区军事代表室,河南洛阳471039 [2]河南柴油机重工有限责任公司,河南洛阳471039

出　　处：《内燃机》2023年第4期44-48,共5页Internal Combustion Engines

摘　　要：通过对某型柴油机氢脆断裂的主轴承盖螺柱进行理化分析和断口形貌观察后发现,在热处理过程中存在脱碳现象,这影响了螺柱调质后硬度检测的准确性,使螺柱实际硬度和抗拉强度超高,降低了螺柱发生氢脆断裂所需的氢含量门槛值。而在螺柱长期服役过程中,氢离子聚集,从而导致氢脆断裂的发生。通过对工艺过程的分析,制定了一系列工艺改进措施,包括防止应力集中、避免热处理过程脱碳、提高硬度检测的精度、控制硬度和抗拉强度的范围,以及降低生产过程中吸氢风险等措施。Through the physicochemical analysis and fracture surface observation of a certain type of diesel engines hydrogen embrittlement of the main bearing cap bolt,it was found that decarburization occurred during the heat treatment process,affecting the accuracy of hardness testing after quenching of the bolt.This led to an excessively high actual hardness and tensile strength of the bolt,lowering the threshold value of hydrogen content required for hydrogen embrittlement.During the long-term service of the bolt,hydrogen ions accumulated,resulting in hydrogen embrittlement.To address this issue,a series of process improvement measures were developed through process analysis,including preventing stress concentration,avoiding decarburization in the heat treatment process,enhancing hardness testing accuracy,controlling the range of hardness and tensile strength,and reducing hydrogen absorption risk during production processes.

关 键 词：柴油机 螺柱 氢脆 断裂 工艺改进 

分 类 号：TK427[动力工程及工程热物理—动力机械及工程]