[2P01-53] Poster Presentation

[2P26] Surface hardening technology of SCM440 steel material to improve the tribological properties using short pulse laser irradiation in PAO4 oil

*Motoki Suzuki¹, Yoshiki Tanaka¹, Yuya Nakamura¹, Naoki Yoshida², Xiaou Liu¹, Satoru Maegawa¹, Fumihiro Itoigawa¹, Shingo Ono¹ (1. Nagoya Institute of technology, 2. NIDEK CO., LTD. Basic Technology Institute, R and D Division.)

In recent years, laser-assisted surface treatment technologies with high precision and efficiency in the production of alloy parts are widely used in the industrial field. Especially in the case of steel materials widely used for sliding components such as bearings, high-precision heat treatment without any removal is required. In this study, a novel method of surface modification for steel materials by carbonization using short pulse laser irradiation in the atmosphere of PAO oil is proposed. After irradiation the hardness of modified surface increased by approximately 7~8 Gpa and improved wear resistance in ball-on-disk reciprocating friction tests. After irradiation, cross-sectional image by using TEM shows the modified layer with a thickness of about 200 nm on the SCM440 surface. This layer consists of amorphous Fe5C2 and Fe3C. Based on these results, the effectiveness of this method as a localized surface hardening treatment for steel materials using carbonization phenomena has been demonstrated.