APPARATUS AND METHOD FOR HEAT TREATING WELDING PART OF MARTENSITIC STAINLESS STEEL SHEET

摘要

PURPOSE: An apparatus and a method for heat treating a welding part are provided which prevents plate fracture of the welding part in the stainless steel manufacturing process welding the front and back parts of the martensitic stainless steel sheet. CONSTITUTION: In a welding line of martensitic stainless steel sheet in which the steel sheet is welded in the width direction by a welding machine that is movably installed at a moving axis, wherein the moving axis is installed at the upper part of a table through which a steel sheet is passed, the apparatus for heat treating the welding part of martensitic stainless steel sheet comprises a heat treating machine installed so that the heating point of heat treatment is positioned on the same line as the spraying point of the welding machine, thereby heat treating only the welding part of the steel sheet welded by the welding machine. The method for heat treating the welding part of martensitic stainless steel sheet comprises the process of performing heat treatment by continuously flame spraying only the welding heat affected zone twice in a moving speed of 410 mm/min when a temperature of the welding heat affected zone by the welding is 450 to 750 deg.C after butt welding the rear end of the preceding steel sheet and the front end of the accompanying steel sheet of the steel sheet.