Development And Application Of High Performance Cover Mold Material H235a

The property of some materials can't conform to the requirement of automobile die in the course of machining and using because of their low strength and their poor foundry properties and their bad machining properties and their low hardness for quenching. Such as gray cast iron (HT250/HT300), Mo-Cr alloy cast iron, ductile iron, cast steel (310-570) etc. However, the development of automobile industry is very rapidly recently as the supporting industry in China. How to supply promptly the die with superior quality become those companies' the chiefly task to make die of automobile. So it is significant of finding some material with superior using quality and machining quality.In the article it was analyzed and explained that the mechanical properties and micro-organization of those material how to be affected by those element such as Cr, Mo, Cu etc. through the method of comparing tests. The chemical components and the rates of alloys are assured in the material H235A. We have made 300 pieces of castings for die of automobile comply with the material and found the technical method for making the kind of material with large quantities of castings. The result of testing and used by customers approved that the kind of new material H235A can ensure the die have good quality with superior machining properties and mechanical properties and longer using ages. Using ages of the new material is two times comparing to those old materials such as gray cast iron (HT300) and Mo-Cr alloy casting iron (MTMoCr). The using age even can be improved to 1.8 million times. The new material can conform to the requirement of those materials for die of automobile. Moreover, The foundry properties of the new material are similar to the one of those old materials gray iron.The new material H235A has be applied to succeed as important casting in the crossbeam die of strong horse truck, a new kind of truck by designed by Dongfeng Motor Co., Ltd. In October 2003. It has be applied to abroad in dies of those automobiles such as king trucks load-self made by Dongfeng Company and light cars made by the Great Wall Company and cars made by Dongfeng Accord Company. The new material has obtained good honor from those plants are engaged in machining dies and those plants using these dies.