アジア太平洋地域の各国で創製された鉄鋼材料の諸特性

Abstract

Half of the sheet metal processing machines manufactured in Japan are exported throughout the Asia Pacific and other regions. The reality, however, is that locally purchased low-cost, poor-quality metal materials are used at overseas factories that have introduced such machinery. Consequently, the processing accuracy stated in machinery catalogs cannot be achieved. Moreover, the characteristics of each lot and roll of materials are known to differ even in the same country and that mechanical properties indicate a wide distribution of variance even within a single specified size. Such inconsistency affects the accuracy of secondary processing. Inconsistency in sheet thickness, for instance, is regarded as one cause of unstable spring-back. Although spring-back supposedly relies on the material rigidness, the sheet rigidness is proportional to the cube of the sheet thickness. Therefore, the effect of even a slight inconsistency in sheet thickness on the difference in rigidity becomes substantial. At the site of secondary processing, however, inconsistency at the stage of material production remains unclear. Some understanding of the situation is applicable to the processing stage and is likely to facilitate the manufacture of products with higher precision. In this study, therefore, procures SPCC materials that are often used in sheet metal processing from several countries in the Asia Pacific region, with the intention of investigating their properties and comparing their characteristics and tendencies by country. Based on those results, the effects on the accuracy of secondary processing are considered.