Endurance performance of conical picks with hardfacing for improving wear resistance

Abstract

Conical picks are representative cutting tools for mechanical excavation equipment using a cutting head. The picks include tungsten carbide (TC) tips on their conical bodies to maintain abrasion resistance. Retaining the TC tips is therefore important to maintain the performance of the picks during operation, and hardfacing can simply and effectively achieve this. This study applied martensitic creep-resistant steels as hardfacing on the nose around a conical pick body. Conical picks with and without hardfacing were tested on the cutting head of a transverse type roadheader. The roadheader with the two types of picks excavated a mixed layer of Mantos and conglomerate at a copper mine in Mexico. After excavating for 24 hrs, the effect of the hardfacing alloys was investigated by visual inspection, measurement of weight loss, scanning electron microscope (SEM), and X-ray computed tomography (CT). Overall, the picks with hardfacing endured better than those without. However, internal investigation by X-ray CT showed a need to decrease voids between the TC and the nose of the conical body where the weld metal did not penetrate.