Method for repairing low-alloy Q355B pit of medium-thickness plate

Abstract

The invention discloses a method for repairing a low-alloy Q355B pit of a medium-thickness plate. The method specifically comprises the following steps: (1) selecting a proper repairing material; (2) adjusting the voltage according to the thickness of the repaired steel plate; (3) the pit points of the steel plate are repaired through a spot welding technology; (4) shoveling the raised part of the repairing point, and performing surface smooth polishing by using a sharpening machine; (5) carrying out surface coloring confirmation; and (6) carrying out surface inspection and judgment on the colored steel plate.

Description

Technical Field

[0001] The invention relates to a method for repairing a pit of a medium-thick plate low-alloy Q355B. Background Art

[0002] During the production process and offline transportation of steel plates, there is a risk of pits on the plate surface due to equipment, crane magnetic heads, straightening, etc., and about 200 tons of steel plates are salvaged and reclassified as unqualified due to pits every year. At the same time, the depth of common pits is relatively deep and can only be salvaged by repair methods. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for repairing pits in medium and thick plate low alloy Q355B in view of the shortcomings of the above prior art.

[0004] The technical solution of the present invention to solve the above technical problems is: a method for repairing pits in medium and thick plate low alloy Q355B, the method specifically comprising the following steps: (1) Select appropriate repair materials; (2) Adjust the voltage according to the thickness of the repaired steel plate; (3) Repair the pits on the steel plate by spot welding technology; (4) Remove the raised areas at the repair point and use a grinding machine to smooth the surface; (5) Confirm the surface coloring; (6) Conduct surface inspection and assessment on the colored steel plates.

[0005] The present invention further defines the scheme: Preferably, the steel plate has a thickness of 20-40 mm.

[0006] Preferably, the repair material is Atlantic CHE422.

[0007] Preferably, in (3), the voltage is adjusted to 90V-100V according to the thickness of the repaired steel plate, specifically, when the thickness is 20-22mm, the corresponding voltage is 90-91V; when the thickness is 23-25mm, the corresponding voltage is 92-93V; when the thickness is 26-28mm, the corresponding voltage is 94-95V; when the thickness is 29-31mm, the corresponding voltage is 96-97V; when the thickness is 32-34mm, the corresponding voltage is 98-99V; when the thickness is 35-37mm, the corresponding voltage is 99-100V; when the thickness is 38-40mm, the corresponding voltage is 100V.

[0008] The beneficial effects of the present invention are as follows: the present invention can solve the surface pits of low-alloy Q355B medium and thick plates with a thickness of 20mm to 40mm, save them through a surface repair method, reduce quality costs, deliver them in time, and avoid a large amount of steel waste. DETAILED DESCRIPTION Example

[0009] This embodiment provides a method for repairing a pit on a medium-thick plate of low-alloy Q355B, where the thickness of the steel plate is 20-40 mm, and specifically includes the following steps: (1) Select Atlantic CHE422 as the repair material; (2) The voltage is adjusted from 90V to 100V according to the thickness of the repaired steel plate. Specifically, the thickness is 20-22mm, and the corresponding voltage is 90-91V; the thickness is 23-25mm, and the corresponding voltage is 92-93V; the thickness is 26-28mm, and the corresponding voltage is 94-95V; the thickness is 29-31mm, and the corresponding voltage is 96-97V; the thickness is 32-34mm, and the corresponding voltage is 98-99V; the thickness is 35-37mm, and the corresponding voltage is 99-100V; the thickness is 38-40mm, and the corresponding voltage is 100V; (3) Repair the pits on the steel plate by spot welding technology; (4) Remove the raised areas at the repair point and use a grinding machine to smooth the surface; (5) Confirm the surface coloring; (6) Conduct surface inspection and assessment on the colored steel plates.

[0010] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A method for repairing pits in medium and thick plate low alloy Q355B, characterized in that: The method specifically comprises the following steps: (1) Select appropriate repair materials; (2) Adjust the voltage according to the thickness of the repaired steel plate; (3) Repair the pits on the steel plate by spot welding technology; (4) Remove the raised areas at the repair point and use a grinding machine to smooth the surface; (5) Confirm the surface coloring; (6) Conduct surface inspection and assessment on the colored steel plates.

2. A method for repairing a pit in a medium and thick plate of low alloy Q355B according to claim 1, characterized in that: The thickness of the steel plate is 20-40 mm.

3. A method for repairing a pit in a medium and thick plate of low alloy Q355B according to claim 1, characterized in that: The repair material is Atlantic CHE422.

4. A method for repairing a pit in a medium and thick plate of low alloy Q355B according to claim 1, characterized in that: In the above (3), the voltage is adjusted from 90V to 100V according to the thickness of the repaired steel plate. Specifically, when the thickness is 20-22mm, the corresponding voltage is 90-91V; when the thickness is 23-25mm, the corresponding voltage is 92-93V; when the thickness is 26-28mm, the corresponding voltage is 94-95V; when the thickness is 29-31mm, the corresponding voltage is 96-97V; when the thickness is 32-34mm, the corresponding voltage is 98-99V; when the thickness is 35-37mm, the corresponding voltage is 99-100V; when the thickness is 38-40mm, the corresponding voltage is 100V.