ALLOY RECOVERY IN 12-PERCENT-CR CONTINUOUS CASTER ROLL WELDING

Type 420 stainless steels (nominally 0.2% C, 12% Cr), and related alloys, are commonly used for cladding continuous caster rolls for steel mills by submerged arc welding. In this study, an acid flux and a basic flux, with Type 420 wires designed for each flux, were used to make claddings unclear a variety of wire feed speed (current) voltage conditions. These various conditions resulted in flux-to-wire ratios as low as 0.3 and as high as 1.5. Deposit composition and hardness properties were then obtained. With the acid flux and either wire, deposit chromium and carbon decreased with increasing flux-to-wire ratio. With the basic flux and either wire, deposit chromium did not vary significantly when the flux-to-wire ratio was varied. But deposit carbon was very high when the wire designed for acid flux was used with the basic flux. Hardness variations with flux-to-wire ratio changes were also noted. It is concluded that deposit composition is independent of flux-to-wire ratio when a basic flux and a wire designed for basic flux are used. But the deposit composition is strongly affected by flux-to-wire ratio when an acid flux is used. It is also shown that deposit compositions markedly different from normal compositions are obtained when a wire designed for acid flux is used with basic flux, or when a wire designed for basic flux is used with acid flux.