An overview on economic machining of hardened steels by hard turning and its process variables

Producers of machined components and manufactured goods are continually challenged to reduce cost, improve quality, and minimize setup times in order to remain competitive. Frequently the answer is found with new technology solutions. In the recent years, there has been increasing interest in hard turning over grinding for machining of hardened steels in automotive, bearing, mold-die making industries. Hard turning is greatly affected by factors like machine tool, cutting tool geometry and materials, cutting parameters, and cooling methods. There are some issues in the process which should be understood and dealt with such as friction and heat generation at the cutting area that can affect the tool life and surface finish apart from other machining results to achieve successful performance. Researchers have worked upon several aspects related to hard turning and came up with their own recommendations to overcome these problems. This article presents an overview on all the factors that influences hard turning operations performance and is an attempt to give a proper understanding of the process. A summary of the hard turning techniques is outlined and further a comparison of hard turning and grinding is discussed with regard to certain evaluation criteria based on process economical efficiency.