CN114147248A - Welding process of low-alloy high-strength structural steel - Google Patents
Welding process of low-alloy high-strength structural steel Download PDFInfo
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- CN114147248A CN114147248A CN202111351044.5A CN202111351044A CN114147248A CN 114147248 A CN114147248 A CN 114147248A CN 202111351044 A CN202111351044 A CN 202111351044A CN 114147248 A CN114147248 A CN 114147248A
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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Abstract
The invention discloses a welding process of low-alloy high-strength structural steel, which comprises the following steps of: (1) cleaning and preprocessing: preprocessing the position of the steel to be welded, and removing redundant leftover materials; (2) preheating: uniformly heating the steel within the range of about 80mm on two sides of the position where the steel needs to be welded; (3) welding: after preheating is finished, welding the welding seams of the welding material layer by adopting electric welding, cleaning the welding layer after the seam welding of each layer is finished in the welding process, and then welding the next layer; (4) heat preservation and slow cooling: after welding of the welding line is finished, covering the welding line and the peripheral area thereof by cotton cloth during heat preservation, preserving heat according to the thickness of the base metal after covering, and simultaneously preserving heat for the double-sided welding line; (5) post-heating: the hydrogen treatment is carried out on the welding material after heat preservation, namely, the welding piece is heated to 350 ℃ and 250 ℃, so that cracks can be effectively avoided in the welding process.
Description
Technical Field
The invention relates to the technical field of welding processes, in particular to a welding process of low-alloy high-strength structural steel.
Background
Structural steel refers to steel that meets certain strength and formability ratings, formability being expressed in elongation after breaking of tensile test, and structural steels are commonly used for load bearing applications, where strength of the steel is an important design criterion, and can be subdivided into: the welding process comprises the steps of welding the structural steel in the using process, along with the progress of scientific technology and the development of national economy, higher requirements on the welding quality, the production efficiency and the product quality of the structural steel are provided, and cracks easily appear in the existing structural steel in the welding process.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides a welding process of low-alloy high-strength structural steel, which can effectively avoid cracks in the welding process and effectively solve the problems in the background art.
In order to achieve the purpose, the invention provides the following technical scheme: a welding process of low-alloy high-strength structural steel comprises the following steps:
(1) cleaning and preprocessing: preprocessing the position of the steel to be welded, and removing redundant leftover materials;
(2) preheating: uniformly heating the steel within the range of about 80mm on two sides of the position where the steel needs to be welded;
(3) welding: after preheating is finished, welding the welding seams of the welding material layer by adopting electric welding, cleaning the welding layer after the seam welding of each layer is finished in the welding process, and then welding the next layer;
(4) heat preservation and slow cooling: after welding of the welding line is finished, covering the welding line and the peripheral area thereof by cotton cloth during heat preservation, preserving heat according to the thickness of the base metal after covering, and simultaneously preserving heat for the double-sided welding line;
(5) post-heating: carrying out hydrogen treatment on the welding material after heat preservation, namely heating the welding piece to the temperature of 250-350 ℃, then carrying out heat preservation again for 2-6h, and carrying out air cooling after heat preservation;
(6) postweld heat treatment: and (3) performing stress relief annealing on the post-heated welding material within the range of 600-650 ℃, performing high-temperature tempering at the temperature lower than the Ac1 point, and performing furnace cooling or air cooling to finish welding.
As a preferable technical scheme of the invention, the preheating temperature in the step (2) is more than or equal to 20 ℃, the heating width is more than 5 times of the plate thickness, and the preheating mode is flame heating, power frequency induction heating or infrared heating.
As a preferable technical scheme of the invention, in the step (3), the interlayer temperature is maintained at 80-200 ℃ during welding, according to the ambient temperature, inspectors can use a temperature measuring tool to monitor the preheating and interlayer temperature, and when the temperature is too low, the welding seam area is subjected to flame heating.
As a preferred technical scheme of the invention, the heat preservation time in the step (4) is determined according to the thickness of the base metal plate, the heat preservation time is calculated according to the thickness of each 25mm and is not less than 0.5 hour, the minimum heat preservation time is not less than 1 hour, the thickness of the heat preservation asbestos plate is overlapped and is not less than three layers, and the heat preservation asbestos cloth is pressed by an iron block to be attached to a workpiece as far as possible;
as a preferable embodiment of the present invention, the temperature of the heat after the step (5) is 20 ℃ and the heating width is 5 times the thickness of the sheet, and the heating method is flame heating.
Compared with the prior art, the invention has the beneficial effects that: the welding process of the low-alloy high-strength structural steel has the following advantages:
1. the hardening degree of steel is reduced by preheating, and the cooling speed of a welding seam and a heat affected zone can be reduced by cooling the heat preservation ring of a weldment after welding, so that cracks can be effectively avoided;
2. by adopting the dehydrogenation treatment, the diffused hydrogen in the weld metal can be accelerated to escape, the hydrogen content in the weld and the heat affected zone is reduced, and the cold crack can be effectively prevented from being generated.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The first embodiment is as follows: a welding process of low-alloy high-strength structural steel comprises the following steps:
(1) cleaning and preprocessing: preprocessing the position of the steel to be welded, and removing redundant leftover materials;
(2) preheating: uniformly heating the steel within the range of about 80mm on two sides of the position where the steel needs to be welded, wherein the preheating temperature is 20 ℃, the heating width is 6 times of the thickness of the steel, and the preheating mode is flame heating;
(3) welding: after preheating, carrying out welding layer by layer on the welding seam of the welding material by adopting electric welding, cleaning the welding layer after the welding of each layer of seam is finished in the welding process, then carrying out next layer welding, wherein the interlayer temperature is maintained at 80 ℃ when welding is carried out, welding workers are forbidden to weld in the back and forth direction without stopping during welding, according to the environmental temperature, inspectors can use a temperature measuring tool to monitor the preheating and the interlayer temperature, and flame heating is carried out on the welding seam area when the temperature is lower than 80 ℃;
(4) heat preservation and slow cooling: after welding of the welding line is finished, covering the welding line and the peripheral area of the welding line by cotton cloth during heat preservation, preserving heat according to the thickness of a base material after covering, simultaneously preserving heat for double-sided welding lines, wherein the heat preservation time is 1 hour, the thickness of heat preservation asbestos plates is overlapped into three layers during heat preservation, and the heat preservation asbestos cloth is pressed by an iron block to be attached to a workpiece as far as possible;
(5) post-heating: carrying out hydrogen treatment on the welding material after heat preservation, namely heating the welding piece to 250 ℃, then preserving heat again for 2 hours, carrying out air cooling after heat preservation, wherein the temperature of post heating is 20 ℃, the heating width is 5 times of the plate thickness, and the heating mode is flame heating;
(6) postweld heat treatment: and (3) annealing the post-heated welding material at the stress relief within the range of 600 ℃, tempering the welding material at a high temperature lower than the temperature of Ac1, and then cooling the welding material in air to finish welding.
Example two: a welding process of low-alloy high-strength structural steel comprises the following steps:
(1) cleaning and preprocessing: preprocessing the position of the steel to be welded, and removing redundant leftover materials;
(2) preheating: uniformly heating the steel within the range of about 80mm on two sides of the position to be welded, wherein the heating temperature is 30 ℃, the heating width is 6 times of the thickness of the steel plate, and the preheating mode is power frequency induction heating;
(3) welding: after preheating, carrying out welding layer by layer on the welding seam of the welding material by adopting electric welding, cleaning the welding layer after the welding of each layer of seam is finished in the welding process, then carrying out next layer of welding, wherein the interlayer temperature is maintained at 100 ℃, welding workers are forbidden to weld in the back and forth direction without stopping during welding, according to the environmental temperature, inspectors can use a temperature measuring tool to monitor the preheating and the interlayer temperature, and when the temperature is too low, the welding seam area is subjected to flame heating;
(4) heat preservation and slow cooling: after welding the welding line, covering the welding line and the peripheral area thereof with cotton cloth during heat preservation, preserving heat according to the thickness of the base metal after covering, simultaneously preserving heat for double-sided welding lines according to the condition that the heat preservation time is 1.5 hours, superposing the thickness of heat preservation asbestos plates into four layers during heat preservation, pressing the heat preservation asbestos cloth by using an iron block, and enabling the heat preservation asbestos cloth to be attached to a workpiece as far as possible;
(5) post-heating: carrying out hydrogen treatment on the welding material after heat preservation, namely heating the welding piece to 350 ℃ for 250-6 h, then carrying out heat preservation again, carrying out air cooling after heat preservation, wherein the temperature of post heat is 20 ℃, the heating width is 5 times of the plate thickness, and the heating mode is flame heating;
(6) postweld heat treatment: and (3) annealing the post-heated welding material at the stress relief within the range of 600 ℃, tempering the welding material at a high temperature lower than the temperature of Ac1, and then cooling the welding material in a furnace to finish welding.
Example three: a welding process of low-alloy high-strength structural steel comprises the following steps:
(1) cleaning and preprocessing: preprocessing the position of the steel to be welded, and removing redundant leftover materials;
(2) preheating: uniformly heating the steel within the range of about 80mm on two sides of the position where the steel needs to be welded, wherein the heating temperature is 40 ℃, the heating width is 6 times of the thickness of the steel, and the preheating mode is infrared heating;
(3) welding: after preheating, carrying out welding layer by layer on the welding seam of the welding material by adopting electric welding, cleaning a welding bead/layer after the welding of each layer of seam is finished in the welding process, then carrying out next layer of welding, wherein the interlayer temperature is maintained at 140 ℃, welding workers are forbidden to weld in the back and forth direction without stopping during welding, according to the environmental temperature, inspectors can use a temperature measuring tool to monitor the preheating and the interlayer temperature, and the welding seam area is subjected to flame heating when the temperature is too low;
(4) heat preservation and slow cooling: after welding the welding line, covering the welding line and the peripheral area thereof with cotton cloth during heat preservation, preserving heat according to the thickness of the base metal after covering, simultaneously preserving heat for the double-sided welding line on two sides for 3 hours, superposing the thickness of the heat preservation asbestos plate into six layers during heat preservation, pressing the heat preservation asbestos cloth by using an iron block to ensure that the heat preservation asbestos cloth is attached to the workpiece as much as possible;
(5) post-heating: carrying out hydrogen treatment on the welding material after heat preservation, namely heating the welding piece to 350 ℃, then preserving heat again for 6 hours, carrying out air cooling after heat preservation, wherein the temperature of post heating is 20 ℃, the heating width is 5 times of the plate thickness, and the heating mode is flame heating;
(6) postweld heat treatment: and (3) annealing the post-heated welding material at the stress relief within the range of 600-650 ℃, tempering at a high temperature lower than the temperature of Ac1, and then cooling in a furnace to finish welding.
Example four: a welding process of low-alloy high-strength structural steel comprises the following steps:
(1) cleaning and preprocessing: preprocessing the position of the steel to be welded, and removing redundant leftover materials;
(2) preheating: uniformly heating the steel within the range of about 80mm on two sides of the position where the steel needs to be welded, wherein the heating temperature is 45 ℃, the heating width is 6 times of the thickness of the steel, and the preheating mode is flame heating;
(3) welding: after preheating, carrying out welding layer by layer on the welding seam of the welding material by adopting electric welding, cleaning the welding layer after the welding of each layer of seam is finished in the welding process, then carrying out next layer of welding, wherein the interlayer temperature is maintained at 130 ℃, welding workers are forbidden to weld in the back and forth direction without stopping during welding, according to the environmental temperature, inspectors can use a temperature measuring tool to monitor the preheating and the interlayer temperature, and when the temperature is too low, the welding seam area is subjected to flame heating;
(4) heat preservation and slow cooling: after welding the welding line, covering the welding line and the peripheral area thereof with cotton cloth during heat preservation, preserving heat according to the thickness of the base metal after covering, simultaneously preserving heat for the double-sided welding line on two sides for 3 hours, superposing the thickness of the heat preservation asbestos plate into four layers during heat preservation, pressing the heat preservation asbestos cloth by using an iron block to ensure that the heat preservation asbestos cloth is attached to the workpiece as much as possible;
(5) post-heating: carrying out hydrogen treatment on the welding material after heat preservation, namely heating the welding piece to 270 ℃, then preserving heat again for 4 hours, carrying out air cooling after heat preservation, wherein the temperature of post heating is 20 ℃, the heating width is 5 times of the plate thickness, and the heating mode is flame heating;
(6) postweld heat treatment: and (3) performing stress relief annealing on the post-heated welding material within the range of 620 ℃, performing high-temperature tempering at the temperature lower than the Ac1 point, and then performing air cooling to finish welding.
According to the invention, the cooling speed after welding can be effectively reduced by preheating the steel before welding, so that the combination and performance of a welding seam and a heat affected zone are improved, the generation of cracks is reduced, the welding residual stress can be reduced through postweld heat treatment, a hardened part is softened, the structure and performance of the welding seam and the heat affected zone are improved, the plasticity and toughness of a welding joint are improved, and the size of a structure is stabilized.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (5)
1. A welding process of low-alloy high-strength structural steel is characterized by comprising the following steps:
(1) cleaning and preprocessing: preprocessing the position of the steel to be welded, and removing redundant leftover materials;
(2) preheating: uniformly heating the steel within the range of about 80mm on two sides of the position where the steel needs to be welded;
(3) welding: after preheating is finished, welding the welding seams of the welding material layer by adopting electric welding, cleaning the welding layer after the seam welding of each layer is finished in the welding process, and then welding the next layer;
(4) heat preservation and slow cooling: after welding of the welding line is finished, covering the welding line and the peripheral area thereof by cotton cloth during heat preservation, preserving heat according to the thickness of the base metal after covering, and simultaneously preserving heat for the double-sided welding line;
(5) post-heating: carrying out hydrogen treatment on the welding material after heat preservation, namely heating the welding piece to the temperature of 250-350 ℃, then carrying out heat preservation again for 2-6h, and carrying out air cooling after heat preservation;
(6) postweld heat treatment: and (3) performing stress relief annealing on the post-heated welding material within the range of 600-650 ℃, performing high-temperature tempering at the temperature lower than the Ac1 point, and performing furnace cooling or air cooling to finish welding.
2. The welding process of a low alloy high strength structural steel according to claim 1, wherein: the preheating temperature in the step (2) is more than or equal to 20 ℃, the heating width is more than 5 times of the plate thickness, and the preheating mode is flame heating, power frequency induction heating or infrared heating.
3. The welding process of a low alloy high strength structural steel according to claim 1, wherein: and (3) when welding is carried out, the interlayer temperature is kept at 80-200 ℃, according to the ambient temperature, inspectors can use a temperature measuring tool to monitor the preheating and interlayer temperature, and when the temperature is too low, the welding seam area is subjected to flame heating.
4. The welding process of a low alloy high strength structural steel according to claim 1, wherein: and (4) determining the heat preservation time in the step (4) according to the thickness of the base metal plate, calculating according to the time that each 25mm is not less than 0.5 hour, wherein the minimum heat preservation time is not less than 1 hour, the thickness of the heat preservation asbestos plate is not less than three layers in superposition during heat preservation, and the heat preservation asbestos cloth is pressed by an iron block to be attached to the workpiece as far as possible.
5. The welding process of a low alloy high strength structural steel according to claim 1, wherein: the temperature of the heat after the step (5) is 20 ℃, the heating width is 5 times of the plate thickness, and the heating mode is flame heating.
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| CN202111351044.5A CN114147248A (en) | 2021-11-16 | 2021-11-16 | Welding process of low-alloy high-strength structural steel |
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101049670A (en) * | 2007-05-11 | 2007-10-10 | 北京城建集团有限责任公司 | Method for hot working and welding heavy plate |
| CN101514430A (en) * | 2009-04-07 | 2009-08-26 | 杭州汽轮铸锻有限公司 | Chromium-molybdenum-vanadium steel and repairing technology for chromium-molybdenum-vanadium steel casting |
| CN102632321A (en) * | 2012-04-23 | 2012-08-15 | 湖南华菱湘潭钢铁有限公司 | Process for welding and repairing cracks of roller end connector of rolling mill |
| CN103143850A (en) * | 2013-03-08 | 2013-06-12 | 国核工程有限公司 | Process for preventing cold cracking of ASTM (American society for testing material) standard high-strength, low-alloy and atmospheric-corrosion-resistance structural steel |
| CN104625322A (en) * | 2014-12-26 | 2015-05-20 | 中誉远发国际建设集团有限公司 | Large non-standard device thick-plate all-position welding method |
| US20150202710A1 (en) * | 2012-03-22 | 2015-07-23 | Hitachi Zosen Corporation | Method of welding structural steel and welded steel structure |
| CN104999186A (en) * | 2015-07-07 | 2015-10-28 | 江苏沪宁钢机股份有限公司 | Thick steel plate low-temperature environment welding technology |
| CN105583506A (en) * | 2016-03-21 | 2016-05-18 | 上海绿地建设(集团)有限公司 | Welding process for high-performance steel |
| CN110587076A (en) * | 2019-09-25 | 2019-12-20 | 淄博海益精细化工有限公司 | Method for welding nickel-based alloy after service in high-temperature and oxidation environment |
| WO2021100218A1 (en) * | 2019-11-21 | 2021-05-27 | 日本製鉄株式会社 | Carbon steel material welding method |
-
2021
- 2021-11-16 CN CN202111351044.5A patent/CN114147248A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101049670A (en) * | 2007-05-11 | 2007-10-10 | 北京城建集团有限责任公司 | Method for hot working and welding heavy plate |
| CN101514430A (en) * | 2009-04-07 | 2009-08-26 | 杭州汽轮铸锻有限公司 | Chromium-molybdenum-vanadium steel and repairing technology for chromium-molybdenum-vanadium steel casting |
| US20150202710A1 (en) * | 2012-03-22 | 2015-07-23 | Hitachi Zosen Corporation | Method of welding structural steel and welded steel structure |
| CN102632321A (en) * | 2012-04-23 | 2012-08-15 | 湖南华菱湘潭钢铁有限公司 | Process for welding and repairing cracks of roller end connector of rolling mill |
| CN103143850A (en) * | 2013-03-08 | 2013-06-12 | 国核工程有限公司 | Process for preventing cold cracking of ASTM (American society for testing material) standard high-strength, low-alloy and atmospheric-corrosion-resistance structural steel |
| CN104625322A (en) * | 2014-12-26 | 2015-05-20 | 中誉远发国际建设集团有限公司 | Large non-standard device thick-plate all-position welding method |
| CN104999186A (en) * | 2015-07-07 | 2015-10-28 | 江苏沪宁钢机股份有限公司 | Thick steel plate low-temperature environment welding technology |
| CN105583506A (en) * | 2016-03-21 | 2016-05-18 | 上海绿地建设(集团)有限公司 | Welding process for high-performance steel |
| CN110587076A (en) * | 2019-09-25 | 2019-12-20 | 淄博海益精细化工有限公司 | Method for welding nickel-based alloy after service in high-temperature and oxidation environment |
| WO2021100218A1 (en) * | 2019-11-21 | 2021-05-27 | 日本製鉄株式会社 | Carbon steel material welding method |
Non-Patent Citations (1)
| Title |
|---|
| 洪松涛: "金属材料与热处理概论", 天津科学技术出版社, pages: 55 - 59 * |
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