CN115029540A - Welding stress relieving process for liquefied natural gas storage tank - Google Patents
Welding stress relieving process for liquefied natural gas storage tank Download PDFInfo
- Publication number
- CN115029540A CN115029540A CN202210044076.9A CN202210044076A CN115029540A CN 115029540 A CN115029540 A CN 115029540A CN 202210044076 A CN202210044076 A CN 202210044076A CN 115029540 A CN115029540 A CN 115029540A
- Authority
- CN
- China
- Prior art keywords
- welding
- storage tank
- natural gas
- furnace
- gas storage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000003466 welding Methods 0.000 title claims abstract description 50
- 238000000034 method Methods 0.000 title claims abstract description 29
- 239000003949 liquefied natural gas Substances 0.000 title claims abstract description 19
- 238000003860 storage Methods 0.000 title claims abstract description 19
- 238000010438 heat treatment Methods 0.000 claims abstract description 31
- 238000004321 preservation Methods 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 6
- 238000001816 cooling Methods 0.000 abstract description 8
- 238000005265 energy consumption Methods 0.000 abstract description 4
- 230000007613 environmental effect Effects 0.000 abstract description 4
- 238000004134 energy conservation Methods 0.000 abstract description 3
- 229910001566 austenite Inorganic materials 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/50—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for welded joints
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/34—Methods of heating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/143—Reduction of greenhouse gas [GHG] emissions of methane [CH4]
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention discloses a welding stress relieving process for a liquefied natural gas storage tank, which comprises the following steps of: putting a 304LN welding piece into an electric furnace, and heating the welding piece to 550-580 ℃; keeping the temperature of the surface of the welding part after the surface is heated; and (5) turning off the power supply, and cooling the welding piece along with the furnace and then taking the welding piece. The method has the advantages of simple process, low heat treatment temperature, wide temperature range, easy operation, low energy consumption, energy conservation and environmental protection.
Description
Technical Field
The invention belongs to the technical field of postweld heat treatment, and particularly relates to a welding stress relieving process for a liquefied natural gas storage tank.
Background
304LN steel is used as a new generation aviation material, has excellent low-temperature characteristics, high toughness and corrosion resistance, can be suitable for various extremely complex environments such as low temperature, high pressure, strong magnetic field and the like, and has wide application fields. The liquefied natural gas storage tank generally adopts plate rolling butt welding, longitudinal welding, pipeline welding and end enclosure welding, welding stress exists in a welding seam, and postweld heat treatment standards and welding stress elimination standards of 304LN material welding parts do not exist at home and abroad. In order to reduce the risk of cracking due to the release of welding stresses and to increase the stability of the can body, this problem must be solved by corresponding stress relief methods.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides the welding stress relieving process for the liquefied natural gas storage tank, which has the advantages of simple process, lower heat treatment temperature, wider temperature range, easiness in operation, low energy consumption, energy conservation and environmental protection.
In order to achieve the purpose, the invention adopts the following technical scheme: a welding stress relief process for a liquefied natural gas storage tank, comprising the steps of:
s1, putting the 304LN welding piece into an electric furnace, and heating the welding piece to 550-580 ℃;
s2, keeping the temperature of the surface of the welding part after the surface is heated;
and S3, turning off the power supply, and taking out the welded part after the welded part is cooled along with the furnace.
In the technical scheme, the temperature rise rate in the step S1 is 50-300 ℃/h.
In the above technical solution, in the step S2, the sheathed thermocouple is used to determine the temperature of the workpiece to be heated, and the sheathed thermocouple is arranged on the surface of the welded part.
In the above technical solution, the heat preservation time in step S2 is 1 h.
In the above technical solution, in the step S3, the weld material is taken out of the furnace and cooled in the air when the furnace temperature is lower than 200 ℃.
The invention has the beneficial effects that:
1. the invention has simple process, lower heat treatment temperature, wider temperature range, easy operation, low energy consumption, energy conservation and environmental protection;
2. According to the invention, the armored thermocouple is adopted to carry out the temperature index of the workpiece, so that the phenomenon that the welding stress cannot be reduced even the heat is preserved for a long time is avoided, and the energy is saved;
3. the invention can be directly cooled in the furnace after the heat preservation is finished, the process is simple, only the conventional electric furnace is needed, and the requirement on equipment is not high;
4. after heat treatment, the welding stress is obviously reduced, and no new phase is formed, so that the original characteristics of the material can be well guaranteed.
Drawings
Fig. 1 is an XRD pattern of example 1 of the present invention.
Figure 2 is an XRD spectrum of example 5 of the present invention.
Detailed Description
The invention is further described with reference to the following figures and specific examples.
In this embodiment:
the welding part is made of 304LN, the size is 400mm multiplied by 400mm, and the thickness is 40 mm;
the welding method of the welding part is TIG welding backing and MAG welding;
the stress detection method is GB/T7704 and 2017 nondestructive testing X-ray stress determination method;
the stress detection position is a weld heat affected zone;
the impact work is V-shaped grooves at a welding seam at the temperature of-196 ℃.
The detailed description is omitted in the embodiments.
Example 1
As shown in fig. 1, a welding stress relieving process for an lng storage tank according to the present embodiment includes the following steps:
S1, heating the welded part to 550 ℃, wherein the heating rate is 80 ℃/h;
s2, preserving heat for 1h when the temperature of the armored thermocouple arranged on the surface of the workpiece reaches 550 ℃;
s3, turning off the power supply to cool along with the furnace, taking the weldment out of the furnace when the temperature of the furnace is lower than 200 ℃, and cooling in the air;
the stress value of the sample before heat treatment is 225MPa, the stress value after heat treatment is 67MPa, and the residual stress is eliminated by 70.3%; at this time, the impact work of the weld joint area is 36J; the phase detection diagram is shown in fig. 1, and the characteristic peaks can be attributed to the FCC austenite phase, which is the (111), (200), (220) crystal planes corresponding to a single austenite, respectively, indicating that no phase transformation occurs during the heat treatment.
Example 2
In an embodiment of the present invention, a welding stress relieving process for a liquefied natural gas storage tank includes the following steps:
s1, heating the welded part to 580 ℃, wherein the heating rate is 50 ℃/h;
s2, starting heat preservation for 1h when the temperature of an armored thermocouple arranged on the surface of the workpiece reaches 580 ℃;
s3, turning off the power supply to cool along with the furnace, taking the welded part out of the furnace when the temperature of the furnace is lower than 200 ℃, and cooling in the air;
example 3
In an embodiment of the present invention, a welding stress relieving process for a liquefied natural gas storage tank includes the following steps:
S1, heating the welded part to 560 ℃, wherein the heating rate is 80 ℃/h;
s2, starting heat preservation for 1h when the temperature of the armored thermocouple arranged on the surface of the workpiece reaches 560 ℃;
s3, turning off the power supply to cool along with the furnace, taking the welded part out of the furnace when the temperature of the furnace is lower than 200 ℃, and cooling in the air;
example 4
In an embodiment of the present invention, a welding stress relieving process for a liquefied natural gas storage tank includes the following steps:
s1, heating the welded part to 570 ℃, wherein the heating rate is 100 ℃/h;
s2, starting heat preservation for 1h when the temperature of an armored thermocouple arranged on the surface of the workpiece reaches 570 ℃;
s3, turning off the power supply to cool along with the furnace, taking the weldment out of the furnace when the temperature of the furnace is lower than 200 ℃, and cooling in the air;
example 5
As shown in fig. 2, a welding stress relieving process for a liquefied natural gas storage tank according to this embodiment includes the following steps:
s1, heating the welding part to 580 ℃, wherein the heating rate is 300 ℃/h;
s2, preserving heat for 1h when the temperature of the armored thermocouple arranged on the surface of the workpiece reaches 580 ℃;
s3, turning off the power supply to cool along with the furnace, taking the weldment out of the furnace when the temperature of the furnace is lower than 200 ℃, and cooling in the air;
The stress value before heat treatment is 235MPa, the stress value after heat treatment is 58MPa, and the residual stress is eliminated by 73.2 percent; weld zone impact work 43J; the phase detection diagram is shown in fig. 2, and the characteristic peaks can be attributed to the FCC austenite phase, which is the (111), (200), and (220) crystal planes corresponding to a single austenite, respectively, indicating that no phase transformation occurs during the heat treatment.
Example 6
In an embodiment of the present invention, a welding stress relieving process for a liquefied natural gas storage tank includes the following steps:
s1, heating the welded part to 575 ℃, wherein the heating rate is 200 ℃/h;
s2, starting heat preservation for 1h when the temperature of an armored thermocouple arranged on the surface of the workpiece reaches 575 ℃;
s3, turning off the power supply to cool along with the furnace, taking the welded part out of the furnace when the temperature of the furnace is lower than 200 ℃, and cooling in the air;
example 7
In an embodiment of the present invention, a welding stress relieving process for a liquefied natural gas storage tank includes the following steps:
s1, heating the welded part to 555 ℃, wherein the heating rate is 130 ℃/h;
s2, starting heat preservation for 1h when the temperature of an armored thermocouple arranged on the surface of the workpiece reaches 555 ℃;
s3, turning off the power supply to cool along with the furnace, taking the welded part out of the furnace when the temperature of the furnace is lower than 200 ℃, and cooling in the air;
Compared with the prior art, the embodiment has the following positive effects
1. The invention has simple process, lower heat treatment temperature, wider temperature range, easy operation, low energy consumption, energy saving and environmental protection;
2. according to the invention, the armored thermocouple is adopted to carry out the temperature index of the workpiece, so that the phenomenon that the welding stress cannot be reduced even the heat is preserved for a long time is avoided, and the energy is saved;
3. the invention can be directly cooled in the furnace after the heat preservation is finished, the process is simple, only the conventional electric furnace is needed, and the requirement on equipment is not high;
4. after heat treatment, the welding stress is obviously reduced, and no new phase is formed, so that the original characteristics of the material can be well guaranteed. It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative examples and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, all within the scope of the appended claims.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (5)
1. A welding stress relieving process for a liquefied natural gas storage tank is characterized by comprising the following steps: the method comprises the following steps:
s1, placing the 304LN welding piece into an electric furnace, and heating the welding piece to 550-580 ℃;
s2, preserving heat after the surface of the welding part is heated;
and S3, turning off the power supply, and taking out the welded part after the welded part is cooled along with the furnace.
2. The welding stress relief process for a liquefied natural gas storage tank as claimed in claim 1, wherein: the temperature rise rate in the step S1 is 50-300 ℃/h.
3. The welding stress relief process for a liquefied natural gas storage tank as claimed in claim 1, wherein: in the step S2, the temperature of the workpiece is determined by using a sheathed thermocouple, and the sheathed thermocouple is arranged on the surface of the welding part.
4. The welding stress relief process for a liquefied natural gas storage tank as claimed in claim 1, wherein: the heat preservation time in the step S2 is 1 h.
5. The welding stress relief process for a liquefied natural gas storage tank as claimed in claim 1, wherein: in step S3, the weld material is taken out of the furnace and cooled in air when the furnace temperature is below 200 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210044076.9A CN115029540A (en) | 2022-01-14 | 2022-01-14 | Welding stress relieving process for liquefied natural gas storage tank |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210044076.9A CN115029540A (en) | 2022-01-14 | 2022-01-14 | Welding stress relieving process for liquefied natural gas storage tank |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115029540A true CN115029540A (en) | 2022-09-09 |
Family
ID=83118475
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210044076.9A Pending CN115029540A (en) | 2022-01-14 | 2022-01-14 | Welding stress relieving process for liquefied natural gas storage tank |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115029540A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103205557A (en) * | 2013-03-12 | 2013-07-17 | 杭州联源重工机械有限公司 | Post-weld heat treatment process for stainless steel workpieces |
| CN105463176A (en) * | 2015-12-02 | 2016-04-06 | 哈尔滨电气动力装备有限公司 | Shell flange postweld heat treatment process method |
| CN110592362A (en) * | 2019-10-25 | 2019-12-20 | 无锡市华立石化工程有限公司 | Postweld heat treatment method for 304L welding part of liquid nitrogen storage tank |
| CN112536543A (en) * | 2020-11-27 | 2021-03-23 | 武汉重型机床集团有限公司 | Welding structure for releasing stress concentration |
| US20210324494A1 (en) * | 2020-03-20 | 2021-10-21 | China University Of Petroleum(East China) | Local heat treatment method for controlling residual stress with primary and auxiliary heating |
-
2022
- 2022-01-14 CN CN202210044076.9A patent/CN115029540A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103205557A (en) * | 2013-03-12 | 2013-07-17 | 杭州联源重工机械有限公司 | Post-weld heat treatment process for stainless steel workpieces |
| CN105463176A (en) * | 2015-12-02 | 2016-04-06 | 哈尔滨电气动力装备有限公司 | Shell flange postweld heat treatment process method |
| CN110592362A (en) * | 2019-10-25 | 2019-12-20 | 无锡市华立石化工程有限公司 | Postweld heat treatment method for 304L welding part of liquid nitrogen storage tank |
| US20210324494A1 (en) * | 2020-03-20 | 2021-10-21 | China University Of Petroleum(East China) | Local heat treatment method for controlling residual stress with primary and auxiliary heating |
| CN112536543A (en) * | 2020-11-27 | 2021-03-23 | 武汉重型机床集团有限公司 | Welding structure for releasing stress concentration |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103447672B (en) | Submerged arc welding process for large-thickness low-temperature steel plate with yield strength of 690MPa | |
| CN103084703B (en) | A kind of large-scale interior empty steel-casting mends built-up welding reproducing method by replacing a damaged part | |
| CN101514430A (en) | Chromium-molybdenum-vanadium steel and repairing technology for chromium-molybdenum-vanadium steel casting | |
| CN101693943A (en) | High speed steel tool heat treatment method | |
| CN107984062A (en) | A kind of welding method of SUS316 austenitic stainless steels and Weldox700E low-alloy quenched and tempered steel different steel welds | |
| CN104942535A (en) | Manufacture technique of tap shells for polar drill rigs | |
| CN103769728A (en) | Process for repair-welding steel casting through flux-cored wire CO2 gas shielded welding | |
| CN103111734A (en) | Method and device for improving underwater wet welding joint structure property | |
| Fan et al. | Water cooling keyhole gas tungsten arc welding of HSLA steel | |
| CN104419884A (en) | Application of cryogenic treatment in eliminating residual stress of titanium alloy electron beam welding | |
| CN103574220A (en) | Hydraulic pressure expansion liner corrosion resistant alloy composite tube and manufacturing method thereof | |
| CN115029540A (en) | Welding stress relieving process for liquefied natural gas storage tank | |
| CN110293287A (en) | A kind of welding procedure of superhigh intensity precipitation-hardening stainless steel | |
| CN103574221A (en) | Machinery expanding lining anticorrosion alloy composite tube and manufacturing method thereof | |
| CN103447712B (en) | A kind of weld metal of high tenacity cryogenic pipelines welding point | |
| CN105018699A (en) | Heat treatment technology for stainless steel | |
| CN109570695B (en) | Process method for H3Cr13 surfacing on surface of 45 steel | |
| KR20210007628A (en) | Manufacturing Method for High-Manganese Cold Drawn Steel Pipes for Cryogenic Usage for the Shipbuilding and Marine Plant and the High-Manganese Cold Drawn Steel Pipes Thereof | |
| CN109530849B (en) | Welding construction method for carbon steel pipeline in acidic environment | |
| CN113373293B (en) | Repair welding heat treatment method for inner wall corrosion area of hydrogenation reactor of large-scale chemical equipment | |
| CN111304494B (en) | Zirconium alloy flexible continuous pipe and manufacturing method thereof | |
| CN103406680A (en) | Process for special-shaped steel butt welding of F22 valve body and P91 matching pipe | |
| CN104561508A (en) | Postweld normalizing method for gas-pressure welding of steel rails | |
| Wang et al. | Hot Deformation Behaviors of S31042 Austenitic Heat-Resistant Steel | |
| CN105983758A (en) | Gray cast iron welding process |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220909 |
|
| RJ01 | Rejection of invention patent application after publication |