The Research Of Corrosive Wear Damage Of Marine Engineering Chain Link

In recent years, with the increasing requirements of ocean engineering, the high chain structure strength is more and more required. Chain links will suffer from the combined effects of corrosion and wear during their service, which promotes each other obviously. At this stage, however, the research on chain coupling effects of corrosion and wear is still not a unified understanding, so it is difficult to accurately assess the strength of the chain in the service period.The prophase work of this paper put forward the assessment method on the accumulative damages of corrosion and wear when the chain link is during the service period. Both the corrosion of chain annulus in complex seawater environment and the wear of contact surface between adjacent links are taken into consideration in this method. However, the marine mooring chain steel material property parameter which is necessary in this method is not selected accurately, and there is no corresponding experiments in verifying the correctness and reliability of the method.For the above-mentioned targets, firstly, using low-carbon and low-alloy steel for the test materials, the tests of hardness, sea-water erosion and corrsion wear resistance are experimented. Test results show that the macro hardness of marine mooring chain steel is about300HV, the corrosion rate in the artificial sea water is0.12mm/year and the wear extent is gradually increased with the increase of load and wear distance, and the trend of increase tends to be linear.Secondly, according to the results of research, the parameters needed in the evaluation method are determined and the evaluation methods are optimized and improved from multiple aspects. The wear performance which is unde different load, rotate speed and time of marine mooring chain steel is analyzed. After that, the wear coefficient k for this kind of steel materials is2.657x10-3. In addition, the calculation interval and the wear surface gap are also improved. These improvements not only enhance the stability of wear calculation, but also greatly shorten the calculation time and improve the computational efficiency. Finally, calculation result got from the improved evaluation method is compared with the test results to confirm the accuracy and reliability of the evaluation. Verification results shows that the simulation values are slightly on the whole bigger than the tested values, but with the increase of load and wear distance, the differences between them will gradually decrease. Within the testing and calculation error, the test values are very good agreement with the simulation results, which proves that the assessment method on the accumulative damages of corrosion and wear is accuracy and reliability.