Failure Analysis Of Bolts On The Hydrogen Compressor

Compressor is an important device in oil refining and chemical production. SINOPECJinmen branch of embellish hydrogenation compressor exhaust valve and cylinder forcommonly used threaded connection, and under normal working state under periodicalalternating load, therefore, must ensure that the connection strength in the working process.Due to the bolt strength influenced by various factors, combined with the actual workingprocess of the bolt may appear in the short-time overload, and poor lubrication materialsinternal processing defects such as influencing factors.Embellish hydrogenationcompressors exhaust valve bolts appear in the working process of the fracture.Bolt as the research object, based on the failure system embellish hydrogenationcompressors bolt failure mode was studied, through carries on the inspection, macro andmicrostructure analysis, material material mechanics performance testing, metallographicexamination, mechanical design and analysis, stress analysis, the structure of the materialchemical composition analysis, bolt etc. The paper studies the embellish hydrogenationcompressors bolt failure mode. Analyze the failure bolt, in a timely and effective mannerfor the failure reason, proposed the repair plan and safe operation of the measures, not onlycan help the factory back to normal production as soon as possible, reduce the economicloss caused by mechanical failure, failure analysis also helps to accurately distinguish theaccident responsibility. At the same time, the analysis results are due to domestic andforeign similar reactor system operation of the equipment management, failure to advanceprevention and repair of equipment has an important reference.Through study found that bolt section have significant fatigue striations, bolt for thefatigue fracture, and fatigue crack is the result of thread root of manufacture or installationdefects and sulfide corrosion pit. In addition, the unreasonable heat treatment caused thematerial hardness from the surface to the core increases gradually, and with wider stripferrite grain, this also is the important cause leading to the bolt fracture failure. Bolt fatigue strength is obtained by intensity is not enough, ANSYS numerical simulation of bolts canbe seen that there is stress concentration. Can determine the bolt failure due to defects ofthe bolt material is local there is stress concentration caused by fatigue failure.Bolt, the author of this paper, the reason of failure from the following six aspects: putforward the corresponding improvement measures: strictly control the pre-tightening force,reliable locking measures, improve the thread on the phenomenon of uneven loaddistribution, the improvement of bolt material heat treatment process, replacement ofmaterials, reduce stress concentration.