All these steel types are difficult to weld. In many cases the steel has been hardened by annealing, and welding can destroy the hardening. In principle, all these steels can be welded with matching ferritic consumables with the aid of preheating and postweld heat treatment to avoid hydrogen cracking in the heat affected zone (HAZ). In the case of repair welding, it is, however, often not possible to preheat or to perform any postweld heat treatment. So, in this case, welding with austenitic stainless or nickel-based consumables is considered to be one of the best methods.
The risk of cracking is reduced by the higher solubility of hydrogen and the greater ductility of the weld metal. There are so many types of low alloy steel on the market today that even specialists have difficulty in keeping track of the entire range. Numerous types of special alloys not classified under existing standards, are marketed by the steel works. Most types can be welded satisfactorily with Unitor Tensile having a tensile strength of 850 N/mm2 . This electrode may be used both for joining and for building-up work. For cargo handling equipment and dredger applications the Unitor Wearmax-327 should also be considered