Improvements in spraywelding materials

摘要

A spraywelding material comprises a mixture of a least two powdered alloys (the word "alloy" is defined to include pure metal in its scope), in which at least one of said alloys is a self-fluxing alloy, and in which (a) there is a difference in melting temperature of at least 10 DEG F. between the self-fluxing alloy and at least one other alloy of the mixture, and (b) the self-fluxing alloy and said other alloy are mutually alloyable below the upper limit of the fusion range of the mixture when sprayed. The self-fluxing alloy may be of the Cu-base or Ni-base type (i.e. containing at least 30% Ni), and may contain P, Li and/or B as fluxing element(s). Examples of suitable Ni-base alloys are, in per cent, The spraywelding material may be composed of a mixture of two self-fluxing alloys, e.g. alloys (1) and (4) above, or a self-fluxing alloy with, e.g. Ni, 18-8 stainless steel, 12-16 straight Cr steel or a Ni-Cr alloy. The material may be sprayed from a powder gun or may be compounded with a plastic material into a wire for use in a wire-type spray gun. The example relates to the coating of a steel shaft in which the shaft is pre-heated, spray-coated and the coating then fused.