PURPOSE: To produce a steel pipe having superior hot workability, weldability and CO2 corrosion resistance by using high Cr steel having low C and N contents and contg. specified amts. of Cu and Ni as stock, forming this stock into a pipe by hot working and heat-treating the pipe under specified conditions.

CONSTITUTION: High Cr alloy steel contg., by weight, <0.06% C+(12/14)N, <0.50% Si, 0.5-1.5% Mn, <0.05% Al, <0.02% P, <0.005% S, 11.5-14% Cr, 2-4% Cu and 2-4% Ni [(1/2)Cu+Ni≥4%] or further contg. 0.001-0.02% Ca is hot worked to produce a steel pipe. This steel pipe is heated to 930-1,050°C, cooled at an air cooling rate or above and tempered at 560-660°C. A steel pipe having very satisfactory hot workability, superior weldability and CO2 corrosion resistance is produced.