Research On Thermal Fatigue Performance And Oxidation Resistance Of H13Stell After RE-N-C-S-V-Bb Multi-elemments Penetrating

The H13models hot die steel, has excellent hardenability, red hardness, good toughness and high temperature performance, are widely used in the aluminum extrusion industries. However, the aluminum extruding molds direct contact with the high temperature ingot, and also withstands the action of high pressure and high temperature, resulting in the extruding molds premature failure and the increase of production costs. On the other hand, the die failures are cause by surface damage; therefore, surface modification and surface strengthening are the most effective way to improve the life of die. Consequent, in this paper, we are used the RE-N-C-S-V-Nb multi-elemments penetrating to improve the performance of H13steel and studied its oxidation resistance and thermal fatigue resistance.The thermal fatigue performance of the untreated H13steel, nitriding H13steel and RE-N-C-S-V-Nb multi-elemments penetrating specimens are investigated from room temperature to650℃using Uddeholm methods. The results indicated that the untreated H13steel arise the tiny crack after200Psychro-thermal cycles, and nitriding H13steel arise the tiny crack after300Psychro-thermal cycles, but RE-N-C-S-V-Nb multi-elemments penetrating specimens produce the tiny crack after500Psychro-thermal cycles. In the2000Psychro-thermal cycles, the cracks in the surface of the untreated H13steel are very coarse and little, and the surface of nitriding H13steel appeared a lot of grain, local area appears small indentation and loose fold structure, but the amount of small cracks in the surface of RE-N-C-S-V-Nb multi-elemments penetrating specimens. In all, the thermal fatigue performance of H13steel is improved by the RE-N-C-S-V-Nb multi-elemments penetrating treatment.The oxidation of the untreated H13steel, nitriding H13steel and RE-N-C-S-V-Nb multi-elemments penetrating specimens are also studied in the temperature of550℃,600℃and650℃. The XRD results showed that the oxide film of the untreated H13steel are composed of Fe2O3and a-Fe, the oxide film of the nitriding H13steel are composed of Fe2O3, but the oxide film of the RE-N-C-S-V-Nb multi-elemments penetrating specimens are composed of Fe2O3, Fe3O4, and a little NbO2. The SEM morphology indicated that many cracks and nodular oxide particle in the surface of the untreated H13steel, however, there is no obvious cracks in the surface of the RE-N-C-S-V-Nb multi-elemments penetrating specimens.The results of the study show that, RE-N-C-S-V-Nb multi-elemments penetrating can effectively enhance the thermal fatigue and high temperature oxidation resistance of H13steel.