METHOD FOR SURFACE TREATING THREADED PART CONSISTING OF METALLIC MATERIAL, METHOD FOR PREVENTING COHESION IN THREADED PART CONSISTING OF METALLIC MATERIAL, THREADED PART CONSISTING OF METALLIC MATERIAL PROVIDED WITH THREADED PART CAPABLE OF PREVENTING COHESION AND THREADED MEMBER CONSISTING OF METALLIC MATERIAL

PROBLEM TO BE SOLVED: To provide a surface treatment method for a threaded part consisting of a metallic material by which the generation of cohesion, deformation, breakage or the like can suitably be prevented even in use at a high temperature. SOLUTION: A male and/or female threaded part is jetted with a shot of 40 to 200 μm having a hardness equal to or above that of the threaded part at a jet velocity of ≥100 m/s or under a jet pressure of ≥0.3 MPa in the case the threaded part is a ferrous metallic material to increase the temperature in the vicinity of the surface to an A3transformation point or above, and is jetted at a jet velocity of ≥80 m/s or under a jet pressure of ≥0.25 MPa in the case the threaded part is a nonferrous metallic material to increase the temperature in the vicinity of the surface to a recrystallization temperature or above. Next, tin powder of 30 to 300 μm is jetted at a jet velocity of ≥80 m/s or under a jet pressure of ≥0.25 MPa, so that the tin element is diffused over the surface of the part so as to be infiltrated. Preferably, the male and/or female threaded part is coated with a seizure preventive lubricant. COPYRIGHT: (C)2005,JPO&NCIPI