WEAR BEHAVIOR OF SHEET METAL FORMING TOOLS MADE FROM NODULAR CAST IRON AFTER MECHANICAL SURFACE TREATMENTS

摘要

Growing demand for lightweight passenger cars has caused increased use of double-side galvanized high-strength steel sheets. These materials lead to augmented abrasive wear of molds and dies made from nodular cast iron.rnConventional methods to overcome these undesirable phenomena are heat treatment of dies, coatings, usage of improved tool materials and more intensive surface finishing operations. An alternative approach is the application of mechanical surface treatments technologies.rnIn this paper the effect of those treatments on the wear behavior of molds and dies in sheet metal forming are described. The investigated methods are: 1. machine hammer peening 2. deep rolling. Both methods promise to increase the surface hardness and thus wear resistance. A combined strip-drawing test is used for the investigation of abrasive tool wear. It is shown that a good surface smoothing in combination with an improved wear resistance can be realized for small quantity production.