Wear Resistance Surfacing
In order for the MIG welders, Arc welders, Stick welders and TIG welders to perform a good hard surfacing or to do an overlaying operation, then a welding procedure has to be done. The welding process must be related to a certain part that is surfaced, as well as to the composition of that part.
The multiprocess welders should know which welding process needs to be used and which method to be applied. There are also several operations that need to be done before the welding such as cleaning, undercutting, etc.
Stick welders, TIG welders, Arc welders, and MIG welders should also be aware of the preheat temperature, as well as about the necessary techniques that need to be done. For example, they have to be aware of the hardsurfacing pattern, the welding wire method – waving or beading, as well as the adjacent beads interface and the post-welding operations – peening and cooling.
The Arc welders, MIG welders, TIG welders and Stick welders have to select the surfacing alloy. Usually there are two separate materials that need to be used – the buildup alloy applied when the part is much worn and has to be reclaimed, and the hardfacing alloy which is more expensive. In general, the hard-surfacing has to be replaced when this hardfacing alloy is worn away.
The multiprocess welders are aware that when the deposit exceeds three layers, various situations may encounter including cracking. Another factor here is the dilution with the base metal. The excessive dilution will result in reduction of the effectiveness. In such cases the poor tie-in and the excessive penetration have to be avoided.
All multiprocess welders confirm that during all welding operations including fabrication, surfacing and repair, the base metal needs to be clean. The cleaning methods applied on the base metal before the welding include shot blasting, grinding, machining and brushing. Also to be considered are the location of the surface and the first layer of the surfacing.