| 摘要 |
PURPOSE:To enhance the brittleness characteristics during use, creep characteristics and high temp. corrosion resistance of a boiler tube and to lower the cost thereof, by forming the austenite type stainless steel boiler tube increasd only in the Si content of the outer surface layer thereof. CONSTITUTION:This boiler tube comprises a steel pipe having a composition as mentioned hereinbelow. That is, it contains 0.03-0.20% C, 0.3-1.0% Si in the internal part thereof, 1.5-4.0% Si in the outer surface layer thereof having a thickness of 0.5-3mm., 0.1-3.0% Mn, 13-25% Cr, 13-40% Ni, 0.5-3.0% one kind or more Mo and W and 0.05-0.5% one kind or more Ti, Nb and V and, according to necessity, further containing 0.001-0.01% B and substantially comprising the remainder Fe. |
