Steel material for composite pressure vessel liner and steel pipe or tube for composite pressure vessel liner

Patent metadata

Field	Value
Publication number	US-10697036-B2
Application number	US-201615556066-A
Country	US
Kind code	B2
Filing date	Mar 7, 2016
Priority date	Mar 16, 2015
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

Steel material for composite pressure vessel liners that, when used as raw material for manufacturing a composite pressure vessel liner, yields a liner having sufficient strength and a high fatigue limit and enables the manufacture of an inexpensive composite pressure vessel is provided. Steel material for composite pressure vessel liners comprises: a chemical composition containing, in mass %, C: 0.10% to 0.60%, Si: 0.01% to 2.0%, Mn: 0.1% to 5.0%, P: 0.0005% to 0.060%, S: 0.0001% to 0.010%, N: 0.0001% to 0.010%, and Al: 0.01% to 0.06%, with a balance being Fe and incidental impurities; and a metallic microstructure in which a mean grain size of prior austenite grains is 20 μm or less, and a total area ratio of martensite and lower bainite is 90% or more.

First claim

The invention claimed is:

1. Steel material for composite pressure vessel liners, comprising:
a chemical composition consisting of, in mass %,
C: 0.10% to 0.60%,
Si: 0.01% to 2.0%,
Mn: 0.1% to 5.0%,
P: 0.0005% to 0.060%,
S: 0.0001% to 0.010%,
N: 0.0001% to 0.010%,
Al: 0.01% to 0.06%, and optionally at least one element selected from the group consisting of Mo: 0.005% to 2.0%, Cr: 0.005% to 3.0% and Ni: 0.005% to 3.0%,
with a balance being Fe and incidental impurities; and
a metallic microstructure in which a mean grain size of prior austenite grains is 20 μm or less, and a total area ratio of martensite and lower bainite is 90% or more.

2. The steel material for composite pressure vessel liners according to claim 1 ,
wherein the chemical composition satisfies a relationship of the following Expression (1):
[Mn]+1.30×[Cr]+2.67×[Mo]+0.30×[Ni]≥2.30  (1)

where [M] denotes a content of element M in mass %, and [M]=0 in the case where the element M is not contained.

3. The steel material for composite pressure vessel liners according to claim 1 ,
wherein the chemical composition satisfies a relationship of the following Expression (2):
[Mn]+1.30×[Cr]+2.67×[Mo]+0.30×[Ni]≥3.00  (2)

where [M] denotes a content of element M in mass %, and [M]=0 in the case where the element M is not contained.

4. A steel pipe or tube for composite pressure vessel liners made of the steel material for composite pressure vessel liners according to claim 1 .

5. The steel pipe or tube for composite pressure vessel liners according to claim 4 , having a wall thickness of 20 mm or more.

6. The steel material for composite pressure vessel liners according to claim 1 ,
wherein the chemical composition contains, in mass %, one or both of Mo: 0.005% to 2.0% and Cr: 0.005% to 3.0%.

7. The steel material for composite pressure vessel liners according to claim 6 ,
wherein the chemical composition satisfies a relationship of the following Expression (1):
[Mn]+1.30×[Cr]+2.67×[Mo]+0.30×[Ni]≥2.30  (1)

where [M] denotes a content of element M in mass %, and [M]=0 in the case where the element M is not contained.

8. The steel material for composite pressure vessel liners according to claim 6 ,
wherein the chemical composition satisfies a relationship of the following Expression (2):
[Mn]+1.30×[Cr]+2.67×[Mo]+0.30×[Ni]≥3.00  (2)

where [M] denotes a content of element M in mass %, and [M]=0 in the case where the element M is not contained.

9. The steel material for composite pressure vessel liners according to claim 6 ,
wherein the chemical composition contains, in mass %, Ni: 0.005% to 3.0%.

10. The steel material for composite pressure vessel liners according to claim 9 ,
wherein the chemical composition satisfies a relationship of the following Expression (1):
[Mn]+1.30×[Cr]+2.67×[Mo]+0.30×[Ni]≥2.30  (1)

where [M] denotes a content of element M in mass %, and [M]=0 in the case where the element M is not contained.

11. The steel material for composite pressure vessel liners according to claim 9 ,
wherein the chemical composition satisfies a relationship of the following Expression (2):
[Mn]+1.30×[Cr]+2.67×[Mo]+0.30×[Ni]≥3.00  (2)

where [M] denotes a content of element M in mass %, and [M]=0 in the case where the element M is not contained.

Assignees

• Jfe Steel Corp

Inventors

• Takagi Shusaku
• Nagao Akihide
• Kimura Mitsuo
• Okano Hiroshi

Classifications

• C21D8/10

  during manufacturing of tubular bodies · CPC title

• Y02E60/32

  Hydrogen storage · CPC title

• F17C1/00

  Pressure vessels, e.g. gas cylinder, gas tank, replaceable cartridge (pressurised apparatus for purposes other than storage, see the relevant subclasses such as A62C, B05B; associated with vehicles, see the appropriate subclass of classes B60 - B64; pressure vessels in general F16J12/00 {; autoclaves B01J3/04; tank vehicles B60P3/22; railway tank wagons for carrying fluent materials B61D5/00; accumulators for supplying fluid under pressure F15B1/04; liquefied gas stoves F24C3/00}) · CPC title

• C22C38/58

  with more than 1.5% by weight of manganese · CPC title

• C22C38/06 Primary

  containing aluminium · CPC title