PRODUCTION METHOD OF PIPE OF Ni-BASED ALLOY, HIGH-FREQUENCY HEAT-BENT PIPE OF Ni-BASED ALLOY AND JOINT PIPE AND BOILER OF Ni-BASED ALLOY

摘要

PROBLEM TO BE SOLVED: To suppress occurrence of cracks of the surface in e.g. welding or bending a pipe made of a high-strength Ni-based alloy which is usable in facilities with the main steam temperature being of the 700°C grade.SOLUTION: A production method of a pipe of an Ni-based alloy includes a pipe production step of producing a pipe (1), a work-hardening step of carrying out work hardening by shot-peening and a recrystallization heat treatment step of heating the work-hardened pipe (1) in such a recrystallization temperature range as to be equal to or higher than a 1/2 of the melting temperature of the material and equal to or lower than the solid solution treatment temperature and as not to cause growth of thick internal crystal grains.SELECTED DRAWING: Figure 1