PURPOSE: To manufacture a stainless steel welded tube having good corrosion resistance in the environment of conc. sulfuric acid and excellent ductility of the welded part by specifying component ranges and manufacturing conditions of the Si-containing stainless steel welded tube.
CONSTITUTION: A welded stell sheet is manufactured by using the steel sheet containing in wt. ≤0.08% C, 5.0-8.0% Si, ≤2.0% Mn, 10-35% Ni, 10-25% Cr and if necessary, one or more kinds selected from the group consisting of 0.5-3.0% Cu, 0.2-2.0% Mo and 0.005-1.0% Pb as the base material. At this time, this steel sheet is formed to the tube body and the seamless welding is executed to this tube body and a welded metal is composed of in wt. ≤0.08% C, 5.0-8.0% Si, ≤2.0% Mn, 10-35% Ni, 10-25% Cr and the balance Fe with impurities and further, Cr, Si and Ni contents are made to satisfy the inequality I, and port heat-treatment to heat to the temp. range of 1050-1150°C is applied.
WADA NORIMI
KOBAYASHI YASUO
EBARA RYUICHIRO
NAKAMOTO HIDEO
YAMADA YOSHIKAZU
NAGANO HAJIME
NAKAMURA MAKOTO
MITSUBISHI HEAVY IND LTD