Hot work tool steels are essential for production and processing aluminium and aluminium alloys. The tools wich are used for aluminium casting are often made of steel: SITHERM 2367, SITHERM S361R,W 400 VMR, DIEVAR and others. There is often chemical and mechanic wear and metal fatigue in processes where hot work tool steel is used. The interaction is a result of chemical reaction between molten aluminium and solid iron at a phase boundary solid/liquid, causing the formation of intermetallic compounds. Consequence of flow of molten aluminium along tool surface is erosion or mechanical wear. In order to increase the life time of the tool it is necessary to examine and limit the interaction between tool steel and molten aluminium.
In diploma work we did a research about the interaction between hot work tool steel and molten aluminium. We created a laboratory device which we used to examine the interaction between tool steel and metalic melt. The experiments were carried out in mel of electrolytic aluminium (purity of 99,7 mas. %) at the temperature 670 °C and 700 °C and 75 rpm and 150 rpm. The result of the interaction is the growth of a reaction layer which is formed of intermetallic phases Fe-Al. We came to the conclusion that following parameters: temperature, the speed of rotating samples and experiments duration time, have an impact on the wear of tool steel. Taking the results into consideration we created an interaction model between hot work tool steel and molten aluminium.
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