Study on the Hardened Case Discrepancy between the Beginning and the End of Laser Scanning in Laser Transformation Hardening

摘要

In laser transformation hardening (LTH), it is a common phenomenon that the discrepancy of hardening effects occurs between the beginning and the end of laser scanning for those parts which have boundaries along the scanning direction, when the laser processing parameters, laser power and scanning velocity, are kept unchanged. The case depth at the erd of scanning path is larger than that at the beginning. And sometime the local surface on the end may be melted. The discrepancy, which results in non-uniform hardening effect, will make the process quality bad. This paper study on the discrepancy and the effects of laser power and scanning velocity, then presents the effective method to control the discrepancy and to improve the laser process.