Multipass butt-welded joint having excellent brittle crack propagation resistance, and welded structure

A crack propagation, welding head technology, applied in welding/welding/cutting items, welding media, welding equipment, etc., can solve problems such as insufficient effect

Inactive Publication Date: 2009-11-11
NIPPON STEEL CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0017] However, the present inventors have confirmed from the results of large-scale fracture tests on multi-layer butt welded joints that, in multi-layer butt welded joints, since cracks propagate inside the weld metal, even if conventional large-scale heat input in a single pass is applied, A method that is effective in butt welded joints cannot be sufficiently effective in multilayer butt welded joints

Method used

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  • Multipass butt-welded joint having excellent brittle crack propagation resistance, and welded structure
  • Multipass butt-welded joint having excellent brittle crack propagation resistance, and welded structure
  • Multipass butt-welded joint having excellent brittle crack propagation resistance, and welded structure

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0183] These are examples of the above-mentioned (1), (2) to (11), and (37) according to the present invention.

[0184] The welded joint was formed under the steel plate conditions and the weld bead conditions shown in Table 1, and the brittle crack growth resistance was measured by the brittle crack growth test. The results are shown in Table 2. In addition, the composition of the steel plate steel grade used is shown in Table 3.

[0185]

[0186] Table 2

[0187]

[0188] Table 3 (mass%)

[0189] Steel type

C

Si

Mn

P

S

Ni

Ti

YP32

0.13

0.19

1.28

0.01

0.003

0.01

YP36

0.12

0.21

1.27

0.007

0.004

0.01

YP40

0.11

0.21

1.3

0.006

0.003

0.01

YP47

0.08

0.24

1.22

0.007

0.002

1.02

0.01

[0190] In Table 1, the specific weld bead is the weld bead that forms ...

Embodiment 2

[0193] These are examples of the present invention of (1), (12) to (23), and (37) above.

[0194] The welded joint was formed under the steel plate conditions and the weld bead conditions shown in Table 4, and the brittle crack growth resistance was measured by the brittle crack growth test. The results are shown in Table 5. In addition, the composition of the steel plate steel grade used is shown in Table 6.

[0195]

[0196] table 5

[0197]

[0198] Table 6 (mass%)

[0199] Steel type

C

Si

Mn

P

S

Ni

Ti

YP32

0.13

0.19

1.28

0.01

0.003

0.01

YP36

0.12

0.21

1.27

0.007

0.004

0.01

YP40

0.11

0.21

1.3

0.006

0.003

0.01

YP47

0.08

0.24

1.22

0.007

0.002

1.02

0.01

[0200] In Table 4, the specific bead is a bead that forms a bead portion with poor fracture r...

Embodiment 3

[0203] These are examples of the present invention of (1), (24) to (36), and (37) above.

[0204] The welded joint was formed under the steel plate conditions and the weld bead conditions shown in Table 7, and the brittle crack growth resistance was measured by the brittle crack growth test. The results are shown in Table 8. In addition, the composition of the steel plate steel grade used is shown in Table 9.

[0205]

[0206] Table 8

[0207]

[0208] Table 9 (mass%)

[0209] Steel type

C

Si

Mn

P

S

Ni

Ti

YP32

0.13

0.19

1.28

0.01

0.003

0.01

YP36

0.12

0.21

1.27

0.007

0.004

0.01

YP40

0.11

0.21

1.3

0.006

0.003

0.01

YP47

0.08

0.24

1.22

0.007

0.002

1.02

0.01

[0210] In Table 7, the specific bead is the bead in which the residual stress is changed.

[...

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Abstract

Disclosed is a multipass butt-welded joint of a steel sheet, which has excellent brittle crack propagation resistance. In the joint, one or more weld layers or welding passes are arranged between a front welding layer and a rear welding layer in a separately spaced state from each other, wherein each of the weld layers or the welding passes has different properties from those of the surrounding materials and can inhibit and terminate the propagation of a brittle crack.

Description

Technical field [0001] The present invention relates to a multipass butt-welded joint (multipass butt-welded joint) having excellent resistance to brittle crack propagation, which suppresses or stops the propagation of brittle cracks generated inside a welded joint, and has the welding The welded structure of the joint. Background technique [0002] When welding steel plates to build welded structures, in order to reduce construction costs and improve welding construction efficiency, the high heat input welding method is usually used. However, in the welded joint formed by the high heat input welding method, the welding heat affected zone (below Sometimes called the "HAZ zone"), the toughness decreases. In addition, the width of the HAZ zone increases, and the fracture toughness value Kc (an index related to brittle fracture) also decreases. [0003] The fracture of the welded joint is caused by the concentration of stress at the defect formed during welding, and the crack is gen...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K9/23B23K31/00B23K35/30B23K103/04
CPCB23K9/025B23K2203/04B23K9/0216B23K31/02B23K35/3053B23K35/3033B23K9/23B23K31/125B23K2103/04
Inventor 石川忠井上健裕桥场裕治
Owner NIPPON STEEL CORP
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