ORCID
https://orcid.org/0000-0001-6126-8252
Abstract
This paper investigates the evolution of retained austenite and residual stresses during and after tempering of carbonitrided 18CrNiMo7-6 low alloy steel carried out using in-situ X-ray diffraction technique. In this case, two carbonitriding treatments with different surface the retained austenite contents of 20 and 54 mass.-% are investigated. The tempering is carried out in a continuous heating mode to 650°C as well as in isothermal mode at holding temperature of 170, 240, and 300°C for 2 hours. During continuous heating at a heating rate of 10°C/min, the retained austenite started to decompose at 290°C. On isothermal holding at 170°C for 2 hours, the retained austenite remained relatively stable at 20 and 54 mass.-% while readily decomposed to less than 5 mass-% on holding at 300°C. On continuous heating, residual stress in martensite continuously relaxes and reaches full relaxation (0 MPa) at about 400°C. During isothermal holding, residual stresses in martensite are increasingly relaxed with increasing holding tempering. Further relaxation of residual stresses is observed during cooling whereas a cyclic variation of the residual stresses in the retained austenite could be determined
Recommended Citation
Katemi, R. (2022). In-situ Observation of Retained Austenite and Residual Stress Evolutions during Tempering of carbonitrided DIN 1.6587 Alloy Steel. Tanzania Journal of Engineering and Technology (TJET), 41(2), 121-130. https://doi.org/https://doi.org/10.52339/tjet.v41i2.785
Publisher Name
University of Dar es Salaam
Included in
Other Engineering Commons, Other Operations Research, Systems Engineering and Industrial Engineering Commons