An investigation of the influence of laser alloying of the surface layer on abrasive wear resistance of cast iron elements

摘要

The purpose of the study was to evaluate the influence of the laser alloying of the coulter flaps working in a sand medium on the intensity of their abrasive wear. The treatment was performed with a dual diode TRUDISK 1000 laser device. Two types of alloying were performed (with boron and the mixture of boron and chromium). The wear experiment was carried out with a "rotating bowl" device to testing wear in a sandy medium. In comparison to the surface layer of the base coulter flaps (only chilled - with white cast iron microstructure) after laser alloying finer, more homogenous and additionally hardened microstructure of the surface layer was achieved. Such microstructure improved the hardness by approx. 2 times for laser alloying with boron and 3 times for the alloying with boron and chromium. Wear tests proved that this translated into over 2-fold improvement in durability of treated coulter flaps. Mass loss was similar in the case of both types of alloying despite of achieving the higher value of hardness by laser alloying with boron and chromium than by alloying only with boron. It may result from some discontinuities observed in the microstructure of the layer containing chromium that was created due to the technology. It was also observed that alloying with boron improved the surface roughness parameters.