Читать книгу Root Cause Failure Analysis - Trinath Sahoo - Страница 131

A wide range of manufacturing processes are used for obtaining the desired size, shape, and properties in stock material which includes primary and secondary shaping processes such as castings, forming, machining, and welding apart from the processes like heat treatment. The selection of inappropriate combination of the process parameters for each of above mentioned manufacturing processes can lead to development of discontinuities, defects, unfavorable transformation, and metallurgical changes and so deterioration in the performance of final product during the service. These imperfections and discontinuities are mostly process specific and can exist in variety of forms due to improper selection of manufacturing process and their parameters. Therefore, due care must be taken by failure analyst to investigate the presence of any defect, discontinuity or unfavorable features in end produced by manufacturing processes and failed prematurely during the service.