Numerical modeling and experimental investigation of the superficial layer of SKD61 steel during laser surface hardening |
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| Authors: | Kwo‐An Chiang Yong‐Chwang Chen |
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| Affiliation: | 1. Department of Mechanical Engineering , National Taiwan University , Taipei, Taiwan 106, R.O.C. Phone: 886–2–23684463 Fax: 886–2–23684463 E-mail: d89522007@ntu.edu.tw;2. Department of Mechanical Engineering , National Taiwan University , Taipei, Taiwan 106, R.O.C. |
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| Abstract: | Abstract Laser heating of SKD61 steel usually causes the formation of a melting layer on the steel surface, which is of poor thermal conductivity and diffusivity. The modified Ashby‐Easterling heat‐transfer equation was used to simulate the temperature distribution for laser surface hardening of SKD61 steel. The phase transformation temperatures of SKD61 in the quenched and as‐received conditions were compared with each other for different laser energy densities. When the laser was focused on the steel, the temperature of the SKD61 was raised. Due to the effect of superheating, the critical phase transformation temperature in laser hardening became higher than the austenized temperature (1010°C) in traditional quenching. However, the critical phase transformation temperature of SKD61 decreased with increasing laser energy density. |
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| Keywords: | laser transformation hardening dendrites temperature distribution field austenite |
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