Plating solution for threaded connection for pipe or tube and producing method of threaded connection for pipe or tube

Abstract

Provided is a plating solution for a threaded connection used for forming a plating film excellent in galling resistance, crevice corrosion resistance, and exposure corrosion resistance. The plating solution contains no cyanide, but contains copper pyrophosphate, tin pyrophosphate, zinc pyrophosphate, pyrophosphate as a metal complexing agent, and a sulfur-containing compound of 40 g/L or less (excluding 0). The sulfur-containing compound includes: a mercapto compound and a sulfide compound defined by Chemical Formula (1); a dimer formed through a disulfide bond of the mercapto compounds; and one or more types of salts thereof: RS—(CHX1)m—(CHX2)n—CHX3X4  (1), where each of m and n is an integer of 1 or 0; each of X1, X2, X3 and X4 is any one of hydrogen, OH, NH2, SO3H, and CO2H, but excluding that X1, X2, X3, and X4 are all hydrogen; and R is any one of hydrogen, a methyl group, and an ethyl group.

Dependencies are inferred from the claim text.