| 摘要 |
PURPOSE:To improve strength and to maintain high-heat strength at 450-450 deg.C even after a long-period heat treatment and creep rupture strength by adding a specific ratio of V to a welding material for a Cr-Mo high-temp. steel. CONSTITUTION:The core wire has the chemical components of the compsn. contg., by wt%, 0.05-0.16% C, <=0.25% Si, 0.50-1.10% Mn, 2.00-3.50% Cr, 0.80-1.50% Mo, and 0.40-0.60% V, and consisting of the balance Fe and inevitable impurities. A coating material contg., by wt%, 30-70% metallic carbonate such as CaCO3, 5-30% metallic fluoride such as CaF2, and 0.5-5% Mg, and contg. others such as deoxidizing agent, arc stabilizer and binder is coated around such core wire. The V is added to the welding material within the range where the decrease of C by the excessive formation of the carbide in a weld metal is obviated in the above-mentioned manner, by which the higher strength is obtd. Fine V4C3 is deposited in the weld metal by the addition of the V, by which the high-temp. strength at 450-500 deg.C even after the long-period heat treatment and the creep rupture strength are maintained.
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