Effect of Machining on the Surface Roughness of 31CrMoV9 and 34CrAIMo5 Steels After Nitriding

Luş H. M., Şahinoğulları E.

European Journal of Sc􀀀ence and Technology, no.21, pp.410-415, 2021 (Peer-Reviewed Journal)


31CrMoV9 and 34CrAlMo5 are high-performance steels used in many industrial applications in which machines and components are exposed to high surface stresses and dynamic loads. Depending on the customer needs, these steels are first machined on CNC machines and then their surfaces are hardened by nitriding. After nitriding, grinding is needed to reduce the surface roughness values of the product according to the customer demand or the need of the production. Grinding is a chip removal process that uses an a grinding wheel as the cutting tool. However, one of the major drawback for grinding process is significant amount of processing costs. For some applications, such as pump drive shaft, it is foreseen that elimination of grinding step in workflow may reduce significantly cost item for the manufacturer. In this study, the machining parameters of hydraulic pump drive shafts produced from 31CrMoV9 and 34CrAlMo5 materials were changed before nitriding process and after nitriding no grinding process was applied and surface roughness after heat treatment was measured. In the final machining process, 54 hydraulic pump drive shaft samples made of both 31CrMoV9 and 34CrAlMo5 steel material were processed and the cutting edge moving value was used as a variable parameter. According to the measurement results, it was observed that the surface roughness of the pump shafts made of both steel materials was negatively affected after the heat treatment, but this change was limited by changing the turning conditions. Finally, by removing the grinding process from the production process, it is aimed to shorten the total production time of the products and reduce the production cost.