A hard-coating on hot work tool steel can be used to obtain higher corrosion resistance, as well as better wear resistance. This study investigates the thermal fatigue performance of AISI H13 hot work tool steel with and without hard chromium plating. Treated specimens were characterized using microstructural analysis, X-ray diffraction analysis and microhardness measurement. The thermal fatigue test is based on cyclic induction heating and water cooling. The specimen was heated to the maximum surface temperature of 670°C followed with water injection to bring the specimen down to a minimum temperature of 25°C. The thermal fatigue testing in this study was conducted using 500 cycles. A vacuum heat treated specimen with a hardness of 47 HRC was used as the reference material. The hard chromium plated layer with a thickness 35 μm had a hardness of 930 HV0.1. The damage factor, defined as crack depth × crack width, of quenched and tempered H13 specimens and hard chromium plated specimens were 800 and 1760, respectively. The damage factor evaluation verified the vacuum heat treated specimen thermal fatigue resistance is superior to that of the hard chromium plated specimen.

The carbide distribution and retained austenite effects in cold work tool steels on their wear behavior are studied using different quenching, tempering and cryogenic processes. Treated specimens were characterized using optical and scanning electron microscopy, hardness measurements, X-ray diffraction as well as wear tests in a block-on-roller method without lubrication. Beside primary carbides being large and non-uniformly distributed in the D2-B specimen, the weight losses of the D2-B specimen (62.4 HRC) quenched and tempered at 200°C was highest among all tested specimens due to substantial retained austenite in the tempered martensite matrix. With the aid of small and uniform dispersed carbides, the DC53 steel specimen (61.3 HRC) showed less weight loss and exhibited the best wear resistance. The weight loss from cryogenically treated specimens was lower than that of non-cryogenically treated one.