Heat Checking -- A Comparison of Five Hot Work Tool Steels For Use In High Pressure Die Casting Dies

摘要

Heat checking is a major cause of failure of high pressure die casting (HPDC) dies. An experimental program was conducted to compare this mode of failure in five die materials: H13, H11, QRO 90, a maraging steel Th-2799 and KDA-1. Nitrided and electro-discharge machined (EDM) H13 samples were also tested. Surfaces and sections of samples were examined, and a new parameter called 'crack ratio' calculated to rate heat checking performance. The results of the experimental program for the five materials, nitrided and EDM samples are reported. The results showed that under the test conditions QRO90 was less susceptible to heat checking than the other materials tested. The results also showed that heat checking performance depends on the inter-relationship between the material, surface treatment and surface condition.