Comparison of the Properties of Cold Work Tool Steels with the Same Hardness but Different Manufacturing Processes The required important properties

The required important properties of cold work tool steels are hardness, wear resistance, suitable toughness and in many cases corrosion resistance. For cold work tool steels, hardness can be well controlled by heat treatment, but steels of the same hardness do not necessarily have similar wear, corrosion resistance or even toughness. These properties are influenced by the chemical composition of the steels and their manufacturing processes. The study is performed on Böhler K390 PM produced by powder metallurgy (PM) process, Böhler K360 ESR made by electro-slag remelting (ESR) methods and Böhler K110 produced conventionally (C). The specimens were heat treated to obtain the same hardness of 61 HRC. It was made a comparative test of the abrasive wear resistance, corrosion resistance and toughness of the heat-treated cold work tool steel test specimens. The comparative test results show that the Böhler K110 steel has the best corrosion resistance against the 20% acetic acid, and the Böhler K390 PM steel has the best wear resistance and toughness. The goal of the research was to find the optimal cold work tool steel quality for special applications (as a function of wear resistance, corrosion resistance and toughness). The K390 reached the best wear resistance which is two times better than the K360 and about ten times better than the K110. About the corrosion test results, it can be concluded that K110 showed the lowest weight loss after the corrosion test, and the K390 and K360 showed higher weight loss and lower corrosion resistance. Impact energy values from the Charpy impact test were the highest in the case of K390 followed by the K360 and the K110. The results were confirmed by the microscopic analysis.