HIGH-PRESSURE HYDROGEN STEEL PIPE, HIGH-PRESSURE HYDROGEN VESSEL AND STEEL PIPE MANUFACTURING METHOD Russian patent published in 2024 - IPC C22C38/02 C22C38/04 C22C38/06 C22C38/18 C22C38/38 C22C38/40 C22C38/58 C22C38/60 C21D8/10 

FIELD: metallurgy.

SUBSTANCE: invention relates to a steel pipe for high pressure hydrogen and a vessel made using such a pipe, used at automotive hydrogen stations. Pipe has a chemical composition containing the following in wt.%: C: 0.05–0.60; Si: 0.001–2.0; Mn: 0.01–5.0; P: 0.030 or less; S: 0.010 or less; N: 0.010 or less; Al: 0.0001–1.00; O: 0.010 or less; H: 0.00010 or less; optionally, at least one element selected from: Mo: 5.0 or less; Cr: 5.0 or less; Ni: 5.0 or less; Cu: 5.0 or less; Co: 5.0 or less; B: 0.01 or less; V: 1.0 or less; W: 5.0 or less; Nb: 0.1 or less; Ti: 0.1 or less; Zr: 0.2 or less; Hf: 0.2 or less; Ta: 0.2 or less; Sn: 0.2 or less; Sb: 0.2 or less; Ca: 0.01 or less; Mg: 0.01 or less and rare-earth metals: 0.5 or less, the rest is Fe and random impurities. Microstructure of steel includes residual austenite in area fractions of 3 % or less (including 0%), and the number of inclusions in the microstructure, having an aspect ratio of 2.0 or more and length of 10 mcm or more, is 15/100 mm² or less.

EFFECT: pipe has high strength and low rate of fatigue crack growth in the area in which ΔK relating to resistance to fatigue crack growth is 10 MPa·m^1/2 or less.

3 cl, 2 tbl