High-heat-input combined welding method for thick-walled high-strength steel

Patent metadata

Field	Value
Publication number	US-12440927-B1
Application number	US-202519220069-A
Country	US
Kind code	B1
Filing date	May 27, 2025
Priority date	Aug 23, 2024
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

A high-heat-input combined welding method for thick-walled high-strength steel includes following steps. First, a steel plate to be welded is machined into an asymmetric double-sided V-groove, with a depth of a front groove ranging from 30 mm to 40 mm. Then, electrogas welding is used to fill and weld the front groove, with a single-pass heat input controlled below 300 KJ/cm. Finally, a back groove is filled and welded, ensuring that the single-pass heat input for the back groove does not exceed that of the front groove. By adopting an asymmetric double-sided V-groove, the steel plate to be welded is divided into front and back sections. The depth of the groove is restricted to limit the heat input during filling welding.

First claim

What is claimed is:

1. A high-heat-input combined welding method for thick-walled high-strength steel, comprising:
machining a steel plate to be welded into an asymmetric double-sided V-groove, wherein a depth of a front groove is 30 mm to 40 mm; then filling and welding the front groove using electrogas welding while controlling a single-pass heat input below 300 kJ/cm; and finally filling and welding a back groove while ensuring that the single-pass heat input of the back groove does not exceed that of the front groove,
wherein, when a back groove depth satisfies H 2 ≤25 mm, flux-cored arc welding is configured for filling welding;
when the back groove depth satisfies 25 mm<H 2 ≤50 mm, flux-cored arc welding is first configured for filling welding; when a remaining groove depth h satisfies following formula, electrogas welding is then configured for filling welding,

h
≤

H
2

-

H
2
2

⁢

tan
2

⁢

α
2

2

-

H
1
2

⁢
tan
⁢

α
2

2

⁢
tan
⁢

α
1

2

tan
⁢

α
2

2

in the formula, h represents the remaining groove depth, H 2 represents the back groove depth, H 1 represents a front groove depth, α 1 represents a front groove angle, and α 2 represents a back groove angle;
when the back groove depth satisfies H 2 >50 mm, triple-wire submerged arc welding is first configured for filling welding; when the remaining groove depth h satisfies the formula, electrogas welding is then configured for filling welding,

h
≤

H
2

-

H
2
2

⁢

tan
2

⁢

α
2

2

-

H
1
2

⁢
tan
⁢

α
2

2

⁢
tan
⁢

α
1

2

tan
⁢

α
2

2

in the formula, h represents the remaining groove depth, H 2 represents the back groove depth, H 1 represents the front groove depth, α 1 represents the front groove angle, and α 2 represents the back groove angle,
wherein when adopting flux-cored arc welding for filling passes, welding current is within 160A-220A, arc voltage is within 20V-23V, welding speed is 10 cm/min-16 cm/min with heat input of 10 kJ/cm-20 kJ/cm, the electrode extension is within 12 mm-15 mm, and the gas current is at 15 L/min-25 L/min,
wherein when performing filling welding using triple-wire submerged arc welding, leading wire welding current is 1160A-1380A with welding voltage of 32V-35V; middle wire welding current is 1100A-1280A with welding voltage of 40V-42V; trailing wire welding current is 950A-1200A with welding voltage of 42V-46V; triple-wire submerged arc welding speed is 35 cm/min-81 cm/min with heat input of 90KJ/cm-260KJ/cm.

2. The high-heat-input combined welding method according to claim 1 , wherein the front groove angle is 30°-40°, the back groove angle is 30°-50°, and a root face depth is 3 mm-5 mm.

3. The high-heat-input combined welding method according to claim 1 , wherein when performing filling welding on the front groove using electrogas welding, welding current is 380A-460A, welding voltage is 38V-45V, welding speed is 3.5 cm/min-4.5 cm/min, single-pass heat input is 200 kJ/cm-300 kJ/cm.

4. The high-heat-input combined welding method according to claim 1 , wherein when performing filling welding on the front groove using electrogas welding, an electrode extension length is 30 mm-35 mm, and shielding gas flow rate is 30 L/min-35 L/min.

5. The high-heat-input combined welding method according to claim 1 , wherein when performing filling welding on the front groove using electrogas welding, a welding torch oscillation amplitude is controlled at 10 mm-15 mm, and with dwell time on each side is 0.3s-0.5s.

Assignees

• Univ Tianjin

Inventors

• Xu Lianyong
• Han Yongdian
• Xue Zhaowei
• Zhao Lei
• Hao kangda

Classifications

• B23K9/0213

  Narrow gap welding · CPC title

• B23K9/035

  with backing means disposed under the seam · CPC title

• B23K9/164

  making use of a moving fluid · CPC title

• B23K33/004 Primary

  Filling of continuous seams · CPC title

• B23K9/173

  and of a consumable electrode · CPC title