Integrity Study of the Machined Surface Quality in Hard Turning

Abstract

Since their appearance, machining techniques have undergone multiple improvements. The processes of shaping materials by removing material have been constantly questioned in order to stay in step with industrial requirements, whatever economic or ecological. Today, the manufacturing engineer must therefore be able to answer a multitude of questions in order to quickly produce parts of the required quality and at low cost. Hard turning is a process that can be described as standard in a number of sectors such as the production of bearing steel 100Cr6 chrome with a hardness of 62 RC, but also turning auto parts steel chromium-manganese cemented hardened gears as 27MnCr5 a hardness of 62 RC. The technical and economic feasibility of machining parts such harshness was made possible thanks to the use of new tool materials with a very high hardness and high chemical stability at high temperatures, such as cubic boron nitride CBN, and with the arrival of new machine tools with significant stability and high precision. Hard turning allows today to produce high-quality surfaces from competing in many cases, operations traditionally reserved for rectification. High speed machining has also showed its competitiveness in applications such as turning parts for gearboxes and drivesystems in hardened materials. This article is a contribution to the study of the integrity of the machined surface in hard turning.