A manufacturer signed an agreement with the supplier to purchase the large and small gears of the oxygen compressor speed increaser. The specifications and quality were signed in accordance with the contract, and the supplier installed them. However, after a period of operation, one day during work, the large gear pushed open the speed increaser cover, the gear broke, and the oil well erupted. All the bolts connecting the base of the speed increaser and the box were broken, and the machine could no longer continue to operate normally.
was entrusted by a court to conduct identification and analysis on the reasons why the broken gear involved in the case "caused the oil well to blow out and the machine could not continue to work normally."
quality analysis results: The
quality analysis expert group discussed and conducted comprehensive quality technical analysis on the relevant information and on-site investigation and inspection of the gear involved in the case, and made the following suggestions and conclusions:
The large gear involved in the case was split into two halves, the top cover of the speed increaser was severely cracked, both sides of the speed increaser base were broken in many places, and the speed increaser bearings were broken. The expert team took some samples from the gear and returned them to the laboratory for testing.
was tested through the sample hardness, metallographic structure, chemical composition analysis and other methods. It was found that the sample contained a large number of inclusions, which is the main cause of cracks. Among them, the alloy elements do not meet the national standard values, and the differences are large. Therefore, the material of the large gear of the speed increaser does not meet the national standards.
