Product Code: ICAL07_1704

The Influence of Various Surface Conditions during Laser Transformation Hardening
Authors:
Tshidiso Seleka, CSIR National Laser Centre; Pretoria Southwest Africa
Sisa Pityana, CSIR; Pretoria Republic of South Africa
Ken Labuschagne, CSIR; Pretoria Republic of South Africa
Tanya Fedotova, Tshwane University of Technology; Pretoria Republic of South Africa
Presented at ICALEO 2007

This study focuses on the influence of different material surface conditions on the absorption characteristics of the laser beam. Flat rolled 5 mm thick locally manufactured Iscor Bennox® wear plate with a similar chemical composition to AISI 1055 was used as base material. This material is within the medium carbon range, which is suitable for transformation hardening. Eight samples were prepared with different surface conditions. Each sample was treated with the same CW CO2 laser using output power settings between 1 and 5 kW. The specimens were sectioned mechanically and prepared metallographically to a surface finish of 1 µm before etching. The size and penetration depth of the heat-affected zone was used as a measure to determine the influence of surface condition on the absorption characteristics of the laser beam. Vickers micro-hardness tests were conducted to confirm that transformation hardening occurred during the laser treatment.