Zebra Line Laser Heat Treated Die Development

The thermal deflection associated with the conventional die heat treating procedure usually requires extra die grinding process to fine-tune the die surface. Due to the size of the production die, the grinding is time consuming and is not cost effective. The goal of the study is to develop a new die heat treating process utilizing the flexible laser heat treatment, which could serve the same purpose as the conventional die heat treating and avoid the thermal deflection. The unique look of the developed zebra pattern laser heat treating process is defined as the Zebra Line. The heat-treating parameters and processes were developed and calibrated to produce the laser heat treating on laboratory size dies, which were subjected to the die wear test in the laboratory condition. The USS HDGI 980 XG3^TM steel was selected to be carried out on the developmental dies in the cyclic bend die wear test due to its high strength and coating characteristic. The hardness measurements, friction index determined from the die wear tests aligned with the 3D surface scanning profile on the test dies indicate that the hardness, dimensions (width, height of the peak and valley) across the heat-treated area and the size of the gap between Zebra Lines dominate the die-wear behavior. In general, higher hardness and smaller gap between Zebra Lines tend to deliver a better wear resistance.