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: 2011-11-16
NIPPON STEEL CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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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

[0184] Welded joints were formed under the steel plate conditions and weld bead conditions shown in Table 1, and the brittle crack growth resistance characteristics were measured by a brittle crack growth test. The results are shown in Table 2. In addition, the component composition of the steel plate steel type 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 a high toughness weld layer.

[0191] It can be seen that in Invention Examples Nos. 1 to 8, even if the brittle cracks spread in the longitudinal direction of the welded joint, the length was short and stopped im...

Embodiment 2

[0194] Welded joints were formed under the steel plate conditions and weld bead conditions shown in Table 4, and the brittle crack growth resistance characteristics were measured by a brittle crack growth test. The results are shown in Table 5. In addition, the component compositions of the steel types used are 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 forming a bead portion poor in fracture resistance.

[0201] As can be seen from Table 5, in Invention Examples Nos. 1 to 8, even if the brittle cracks spread in the longitudinal direction of the welded joint, the length was short and stopped im...

Embodiment 3

[0204] Welded joints were formed under the steel plate conditions and weld bead conditions shown in Table 7, and the brittle crack growth resistance characteristics were measured by a brittle crack growth test. The results are shown in Table 8. In addition, the component composition of the steel plate steel type 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 was changed.

[0211] As can be seen from Table 8, in Invention Examples Nos. 1 to 8, even if the brittle cracks propagated, their lengths were short and stopped immediately.

[0212] Industrial Utilizatio...

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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; multipass butt-welded joint) having the property of suppressing or stopping the propagation of brittle cracks generated inside a welded joint, that is, excellent resistance to brittle crack growth, and a welded joint having the same property. Joint welded structure. Background technique [0002] When welding steel plates to build welded structures, in order to reduce construction costs and improve welding construction efficiency, high-energy-input welding methods are usually used, but in welded joints formed by high-input energy welding methods, the welding heat-affected zone (hereinafter Sometimes called "HAZ zone"), the toughness decreases, and the width of the HAZ zone increases, and the fracture toughness value Kc (indicator related to brittle fracture) also decreases. [0003] The fracture of the welded joint is caused by stress concentration at a defect ...

Claims

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Application Information

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