.190 Diesel Engine Crankshaft Fracture Failure Analysis

Diesel engine industry is one of important mechanical industry in our country. The diesel engine is the major power installation of automobile, agricultural machinery, construction machinery, boats, diesel locomotives, oil rigs, military and general machinery, mobile equipment, and standby power station. The 190 diesels are middle and high power internal combustion engine, primarily used in oil drilling, ships and auxiliary power generation, and other fields. With the needs of the social and economic development and the improving of people's awareness of quality, the internal combustion engine must possess higher reliability and longer service life.The crankshaft is one of important component of diesel. The quality of the crankshaft is direct affect the engine performance and life. The crankshaft receive the unceasingly cyclical alternation loading, bear various stress such as bending, torsion, impingement, high temperature, and corrosion, so the operational environment of crankshaft is very complex. Before the crankshaft fracture usually is a sudden accident without omen, once the failure happen it will cause serious aftereffect. Crankshaft failure result in not only a lot of direct economic losses, but also more greater indirect economic losses including the credibility of enterprises and market competitiveness of products. Therefore, in order to avoid diesel engine crankshaft failure recurring, improve its quality, prolong its life, enhance security and service reliability of diesel engine, the early fracture analysis is very necessary. The significance of failure analysis consists in finding out the cause of failure, and bringing forward improvement suggestion and precautionary measure, so failure analysis is an important part in reliability technical.In this paper, several kinds of failures mechanism of middle and high power 190 diesel engines crankshaft have been researched systematically. With electronic probe, metallographic image analyzer, direct reading spectrometer, and stereo light microscopes, we have analyzed the macro and micro fracture morphology of crankshaft, and analyzed and summarized systematically raw material, thermal processing inherent structure and surface processing quality. Then we find out many reason caused middle and high power 190 diesel engine crankshaft failure, illustrate fracture mechanism and the general rule of the crankshaft, and propose a series of way on technical improvements. Through these measures we can effectively control the internal structure and appearance quality of crankshaft, and prevent crankshaft early failure happening.In this paper, the early failure analysis of 190 diesel engine crankshaft is based on the results of physical and chemical tests, and guided on metal materials theory. And many of the recommendations and improvement measures have been adopted and applied to crankshaft production in Jinan Diesel Engine Co., Ltd. These guarantee the 190 diesel crankshaft super-quality, and have got user's positive comment. By these kinds of researches we hope that the crankshaft quality would be controlled by quantitative analysis instead of experience and habits operation, and the Chinese crankshaft manufacturing industries of middle and high power internal combustion engine would be got sustained and rapid development.