Welding is commonly used in die cast tools for repair and modification. Maraging steel is used extensively for welding die cast dies.
Reports of failures of such welds have probably resulted from faulty operation of the welding, or have occurred in the die cast die’s parent metal rather than in the weld body itself. Welding by maraging steel involves certain precautions; normally when welding with H-13 the die cast die insert steel is preheated to around 842-896 degrees F; the welding should take place at that elevated temperature to minimize thermal shock. The welding of maraging steel takes place at room temperature and the die cast insert is kept cool by overlaying the weld by successive small amounts instead of all at once. This avoids the introduction of heat to the die cast die insert in quantities sufficient to age-harden the maraging steel, or to affect the parent insert material. The weld is normally applied with the use of argon-arc.The resulting weld is soft and easily machined. It must not, however, be used in the die cast process until it has been properly aged-hardened by the normal treatment at a temperature of 900 degrees F for 3-hrs. At this temperature no effect is made on the parent H-13.Street, A.C. The Die Casting Book. Red Hill, England: Portcullis Press LTD, 1977. Print.