Patent ID: 8211039
Filing Date: 2012-07-03
Classification: A61M,B23K,C21D,Y10T

Abstract:
1. In a medical guide wire having a core wire formed of a flexible elongate member, a helical spring body inserted to a distal end portion of said core wire to be placed around said core wire, and a head plug provided at distal end tips of both said core wire and said helical spring body by means of a welding member, and a synthetic layer coated at least on an outer surface of a proximal portion of said core wire; said core wire made of austenitic stainless steel wire treated with a solid solution procedure, and drawn at a wire-drawing procedure and then heat treated at low temperature of 400° C.-495° C.; a final wire-drawing procedure defined after repeating at least more than a single set of procedures with a combination of said wire-drawing procedure and said heat-treating procedure as the single set; said core wire being rendered with a whole cross sectional reduction ratio as 90%-97.6% until said core wire is subjected to said final wire-drawing procedure; said core wire having 8% or more as a total incre.ase rate of a tensile rupture strength attained due to said heat treatment procedure until said core wire is subjected to said final wire-drawing procedure; said core wire being subjected to predetermined turns of twist at low temperature of 380° C.-495° C. due to an electrical resistance caused by energizing said core wire after finishing said final wire-drawing procedure; said core wire being heat treated at low temperature of 340° C.-420° C. with the use of a heat generated when said synthetic layer is coated on said outer surface of said core wire after treating said distal end portion of said core wire with a mechanical procedure including grinding or pressing procedure; said core wire having 2% or more as a total increase rate of a tensile rupture strength attained each time when said core wire is subjected to said heat treatment procedure after said core wire is subjected to said final wire-drawing procedure; and said core wire having 10% or more as a total increase rate of a tensile rupture strength attained each time when said core wire is subjected to said heat treatment procedure.