Depending on the use of the workpiece to be hardfaced, the weld metal shall meet the most varied demands. These can be cited as follows:
- Hardness in the As-Welded Condition
- Red Hardness under Thermal Loads
- Resistance to Metal-to-Metal Wear
- Abrasion Resistance to Frictional and Grinding Wear
- Impact Strength
- Corrosion Resistance
- Resistance to Scaling
In some cases, more than one of these modes of load may occur simultaneously, so that the weld metal must posses the respective properties. Hence, a conscientious selection of the proper weld metal will be a must. Of course, there doesn't exist a weld metal possessing all these properties in full measure. Nevertheless, in most cases it will be possible to find a satisfactory compromise in practice.