Abrasion resistance of drill bit steels in flowing saltwater

A common type of rock drill bits is a steel head studded with cemented carbide buttons. The function of the steel is mainly to hold the buttons in place while the buttons do most of the rock crushing. However, a significant amount of wear also occurs on the steel matrix so also this material must provide adequate wear resistance. Flushing media is provided to the drilling zone. Preferably, the water is fresh water but in certain geographical areas supply of fresh water is scarce. Bringing fresh water in such areas is costly and sea water or mine water can be used instead. This will expose the equipment, and the drill bit in particular, to more or less corrosive media and possibly change the wear mechanisms of the tool. In this four drill bit matrix steels were tested in a lab scale test simulating the rock drilling including supply of cuttings. During the test the contact zone between the button and the rock was flushed with either fresh water or salty water. The wear rate was measured and the wear scar was studied using SEM and EDS to show the influence of salinity on matrix steel wear.