Effect of heat treatment and batch-to-batch material variations on microstructure of C38 steel

Abstract

Despite steels from different manufacturers abiding by the same standard specifications, tool wear during grinding of these materials seems to progress differently when comparing batch to batch. Therefore, an investigation was made into the different batches in order to explain this difference in grindability between them. Samples of C38 steel from two different batches were used and heat treated in the same way at three different temperatures. The techniques used in this investigation to assess the difference between batches were light optical microscopy as well as hardness testing. Some differences were observed between the batches before heat treatment but after the heat treatment had been performed there were no differences that could be discerned with an optical microscopy. The hardness tests showed a very small difference where one batch was harder by a maximum of 10 HV. With the tools used in this lab no differences that could lead to a variation in grindability was found. To further investigate the question, more tests need to be run.