Open Access

ARTICLE

Effect of Poly-Alkylene-Glycol Quenchant on the Distortion, Hardness, and Microstructure of 65Mn Steel

Thi Xuan Tran¹, Xuan Phuong Nguyen², Duong Nam Nguyen³, Dinh Toai Vu¹, Minh Quang Chau⁴, Osamah Ibrahim Khalaf⁵, Anh Tuan Hoang^6,*

1 Hanoi University of Science and Technology, Hanoi, Vietnam
2 Ho Chi Minh City University of Transport, Ho Chi Minh City, Vietnam
3 Vietnam Maritime University, Haiphong, Vietnam
4 Industrial University of Ho Chi Minh City (IUH), Ho Chi Minh City, Vietnam
5 Al-Nahrain Nanorenewable Energy Research Center, Al-Nahrain University, Baghdad, Iraq
6 Ho Chi Minh city University of Technology (HUTECH), Ho Chi Minh City, Vietnam

* Corresponding Author: Anh Tuan Hoang. Email:

Computers, Materials & Continua 2021, 67(3), 3249-3264. https://doi.org/10.32604/cmc.2021.015411

Received 19 November 2020; Accepted 03 January 2021; Issue published 01 March 2021

Abstract

Currently, the 65Mn steel is quenched mainly by oil media. Even though the lower cooling rate of oil compared to water reduces the hardness of steel post quenching, the deforming and cracking of parts are often minimized. On the other hand, the oil media also has the disadvantage of being flammable, creating smoke that adversely affects the media. The poly alkylene glycol (PAG) polymer quenchant is commonly used for quenching a variety of steels based on its advantages such as non-flammability and flexible cooling rate subjected to varying concentration and stirring speed. This article examines the effect of PAG polymer quenching solution (with concentrations of 10% and 20%) on deformation, hardness, and microstructure of C-ring samples made of 65Mn steel. Furthermore, the performance of PAG polymer quenchant is also compared with those of two common quenching solutions: Water and oil. When cooling in water, the C-ring samples had the largest deformation and 2 times higher than the results obtained when a 10% PAG solution was used. In particular, similar levels of deformation on the C-ring samples were observed in both cases of 20% PAG solution and oil as the primary quenching media. Furthermore, the hardness level measured between the sampled parts quenched in the 20% PAG solution appeared to be more uniform than that obtained from the oil-quenched sample. The study of the microscopic structure of steel by optical microscopy combined with X-ray diffraction showed that the water hardened sample exhibited cracks and comprised of two phases, martensite and retained austenite. According to the results of Electron Back Scattering Diffraction (EBSD) analysis and backscattering electronic image (BSE), the content of austenite residue in the sample when the sample was cooled in PAG 10 and 20% solution was 3.21% and 4.73%, respectively and smaller than the measurements obtained from oil quenching solution. Thus, the 65Mn steel is cooled in 20% PAG solution for high hardness and more evenly distributed than when it is quenched in oil while still ensuring a small level of deformation. Therefore, the PAG 20% solution can completely replace oil as the main media used to quench the 65Mn steel.

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Citations