Effect of Composition and Processing on the Thermal Fatigue Resistance and Toughness of High Performance Die Steels / Die Materials for Critical Applications and Increased Production Rates
This is a two-phase effort. The objective of the first phase was to improve the average die life of a die casting die. It resulted in several important accomplishments. The project evaluated four different steels and identified that KDA-1 steel is clearly superior to H-13 steel for thermal fatigue resistance. KDA-1 performance is attributed to the lower silicon and vanadium present in the steel. Thermal cycling samples were quenched under three cooling conditions. Evaluating the effect of the quenching rate indicates that samples quenched at the fastest rates exhibit the best resistance to thermal fatigue. Charpy-V notch results confirm a significant increase in toughness with temperature for all steels; and higher toughness values for steels that were quenched in oil (i.e. fastest quenching rates).