2003 Volume 11 Issue 4 Pages 36-43
In the automobile industry, steel component parts are required to have high strength, light weight and high quality. It is important to reduce the variability of the quality characteristics of these products during the manufacturing processes, especially in the forging process. To reduce the variability of the process, an experiment was conducted and results were summarized as follows:(1)In order to evaluate the strength of the products, it is necessary to study through the evaluation by the Hooke's law and transformability. (2)The magnitude of useless energy calculated from the study of transformability was 250 times of the one calculated from the Hooke's law. (3)Among the forging process,there is more room for improvement in the shot blasting process. (4)The gain in S/N ratio was 7.2db under the optimum condition. (5)The gain calculated from the loss function was 278 million yen per year.
