METHOD FOR THERMAL TREATMENT OF STEEL CONSTRUCTIONS WITH STRESS CONCENTRATORS Russian patent published in 2003 - IPC

FIELD: mechanical engineering. SUBSTANCE: heating stress concentration zones by laser beam within the range of AinitC1

-AfinC1 to temperature enabling after cooling process formation in surface layer of martensite structure with hydrogen content of 0.22-0.25 wt% and dislocation density of 2,7...3,0•10¹¹ cm^-2; during heating process, providing additional cooling of surface under treatment with cooling liquid. Distance from center of laser spot directed to said surface to cooling liquid spreading front boundary on part surface is determined by ratio: b=R+0.9-1.1 mm, where b is distance from center of laser spot directed to said surface to cooling liquid spreading front boundary; R is radius of laser spot on surface under treatment. Method is used for imparting desired set of qualities to parts having stress concentrators and adapted for operation under complex of heavy-duty forces. EFFECT: increased impact toughness, cyclic strength and wear resistance. 2 dwg, 6 tbl