METHOD FOR PRODUCING HIGH-STRENGTH SEAMLESS CR-NI ALLOY PIPE

文件类型：PDF文档
文件大小：1064K
Disclosed is a method for producing a high-strength seamless Cr-Ni alloy pipe which has excellent hot workability and stress corrosion cracking resistance while having high strength by increasing the content of nitrogen, and does not cause cracking into two pieces during piercing-rolling, characterized by subjecting a seamless base pipe obtained by hot-working through an inclined piercing rolling process using a billet made of an alloy containing, in terms of mass%, C (0.05% or less), Si (1.0% or less), Mn (less than 3.0%), P (0.005% or less), S (0.005% or less), Cu (0.01 to 4.0%), Ni (25% or more but less than 35%), Cr (20 to 30%), Mo (0.01% or more but less than 4.0%), N (0.10 to 0.30%), Al (0.03 to 0.30%), O (oxygen, 0.01% or less), REM (rare earth elements, 0.01 to 0.20%), and Fe and impurities as the remainder, and satisfying the requirement represented by formula (1) to a solution heat treatment, followed by cold-working. N × P / REM ≤ 0.10 Formula (1) In formula (1), P, N, and REM represent the contents (mass%) of P, N, and REM, respectively. The Cr-Ni alloy may contain one or more elements selected from W, Ti, Nb, Zr, V, Ca, and Mg.