| 摘要 |
PURPOSE:To manufacture titled steel having high strength without preheating and heat treatment for removing residual stress, by making the martensitic transformation point near room temperature by improving the composition of the stainless steel, and after repairing casting defects by welding at room temperature, causing above-mentioned transformation by heat treatment. CONSTITUTION:Stainless cast steel composed of <=0.1% C, <=10% Si, 5.0-8.0% Mn, 13.0-15.0% Cr, 4.0-6.0% Ni, 0.5-1.0% Mo by weight and the balance Fe with impurities is smelted. After natural cooling of the stainless cast steel at room temperature or above, casting defects are repaired by welding at room temperature under austenitic state. By this way, preheating and annealing for removing residual stress become unnecessary. Then, after heating to above 200 deg.C, it is cooled to below -100 deg.C to cause martensitic transformation, and martensitic stainless cast steel is manufactured. |
