CN105203625A - Magnetic evaluation method for residual stress relieving effect in postweld heat treatment - Google Patents
Magnetic evaluation method for residual stress relieving effect in postweld heat treatment Download PDFInfo
- Publication number
- CN105203625A CN105203625A CN201510580478.0A CN201510580478A CN105203625A CN 105203625 A CN105203625 A CN 105203625A CN 201510580478 A CN201510580478 A CN 201510580478A CN 105203625 A CN105203625 A CN 105203625A
- Authority
- CN
- China
- Prior art keywords
- peak
- value
- heat treatment
- magnetic signal
- micro
- 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.)
- Granted
Links
Abstract
The invention relates to a magnetic evaluation method for a residual stress relieving effect in postweld heat treatment. The method comprises the steps of measuring a micro magnetic signal of an area to be evaluated before heat treatment according to a preset acquisition path, and recording the acquired micro magnetic signal and a corresponding detection point position, so as to acquire a first peak value and a first maximal gradient value of the acquired micro magnetic signal; acquiring a micro magnetic signal of the area to be evaluated after the heat treatment at the detection point position in the previous step, so as to acquire a second peak value and a second maximal gradient value of the acquired micro magnetic signal; calculating a peak value decrement amount of the second peak value and the first peak value as well as a gradient value difference value between the second maximal gradient value and the first maximal gradient value, so as to obtain a first specific value of the peak value decrement amount to the first peak value as well as a second specific value of the gradient value difference value to the first maximal gradient value; if the first specific value and the second specific value meet preset conditions, judging that after the heat treatment, the welding residual stress of the area to be evaluated achieves an expected effect. The magnetic evaluation method is simple to implement, high in speed and accurate in evaluation result.
Description
Technical field
The present invention relates to detection technique field, particularly relate to the magnetic evaluation method that unrelieved stress effect is eliminated in a kind of post weld heat treatment.
Background technology
Welding residual stress is that its production process is as follows by the interactive result of many factors: the compressive plastic deformation that during welding, the uneven generation of heat input is uneven; During cooling, the material that plastic yield has occurred is subject to again the restriction of adjacent material, can not free shrink thus formed tension, perpendicular to bead direction welding residual stress distribution roughly present " W " shape.
Welding residual stress is the major reason causing welded structure to lose efficacy, and therefore needs to eliminate welding residual stress.Now carry out post weld heat treatment to eliminate welding residual stress to welded structure in the art, during to make heating, the unrelieved stress of material exceedes the yield stress at this temperature, and plastic yield is discharged.Because heat treatment on spot is subject to the impact of external environment comparatively greatly, easily appearance heating inequality, heating-up temperature do not reach the phenomenon such as re-set target and temperature retention time deficiency, thus cause the effect eliminating unrelieved stress not meet the demands, and cause potential safety hazard.Therefore, butt welded seam is needed to carry out residual stress measurement.
At present, the residual stress measuring method of quantitative detection has electrical measuring method, flash spotting, x-ray method etc., but these measuring methods are owing to adopting contact type measurement, region surface to be evaluated is needed to have higher smooth finish, produce slight constructural to measured region to destroy, sense cycle is long and operating process is complicated.Therefore need a kind of harmless, fast, qualitative evaluation post weld heat treatment eliminates the method for unrelieved stress.
Summary of the invention
An object of the present invention is to provide a kind of post weld heat treatment to eliminate the magnetic evaluation method of unrelieved stress effect, to solve Measuring Welding Residual Stresses cycle long complicated operation in prior art and to treat the technical matters that evaluation region has higher requirements.
For achieving the above object, embodiments provide the magnetic evaluation method that unrelieved stress effect is eliminated in a kind of post weld heat treatment, comprising:
According to micro-magnetic signal in region to be evaluated before the thermal treatment of default collection path measurements, and record gather micro-magnetic signal and corresponding check point position, with obtain the first peak peak value of the micro-magnetic signal of collection and the first greatest gradient value;
Gather micro-magnetic signal in region to be evaluated after thermal treatment according to check point position in previous step, identical default collection path, with obtain the second peak-to-peak value of the micro-magnetic signal of collection and the second greatest gradient value;
Calculate the peak-to-peak value reduction of described second peak-to-peak value and described first peak peak value and the Grad difference of described second greatest gradient value and described first greatest gradient value, with the second ratio of the first ratio and described Grad difference and described first greatest gradient value that obtain described peak-to-peak value reduction and described first peak peak value;
Judge whether described first ratio and described second ratio accord with pre-conditioned, if meet pre-conditioned, after thermal treatment, the welding residual stress in region to be evaluated produces a desired effect.
Alternatively, described default collection path orthogonal in weld seam, and extends to this weld seam both sides predeterminable range respectively.
Alternatively, described predeterminable range be weld width, weld seam zone of influence width and redundant wide and.
Alternatively, described predeterminable range is 100mm
Alternatively, the collection step-length gathering micro-magnetic signal in the region to be evaluated before and after thermal treatment is 0.5mm ~ 1mm.
Alternatively, describedly judge whether described first ratio and described second ratio accord with pre-conditioned, if meet pre-conditioned, after thermal treatment, region to be evaluated has been eliminated in the step of unrelieved stress, be describedly pre-conditionedly:
The curve of micro-magnetic signal in the region to be evaluated after thermal treatment tends to level, the first ratio >=50% and the second ratio >=50%.
Alternatively, the curve of micro-magnetic signal in the region to be evaluated after described thermal treatment tends to the following formula of horizontal demand fulfillment:
dH
2/dx≤3(A/m)/mm。
The evaluation method that the embodiment of the present invention provides can judge whether the unrelieved stress of weldment after heat treatment around weld seam reaches the elimination of level of expection, thus avoid weldment because not reaching the requirement of eliminating unrelieved stress after thermal treatment in use potential safety hazard.The invention process is simple, and speed is fast, and evaluation result is accurate.
Accompanying drawing explanation
Can understanding the features and advantages of the present invention clearly by reference to accompanying drawing, accompanying drawing is schematic and should not be construed as and carry out any restriction to the present invention, in the accompanying drawings:
Fig. 1 is the schematic flow sheet of the magnetic evaluation method of the post weld heat treatment elimination unrelieved stress effect that one embodiment of the invention provides;
Fig. 2 is that the welded plate adopted in one embodiment of the invention presets detection path profile;
Fig. 3 is that the welded tube part adopted in further embodiment of this invention presets detection path profile.
Embodiment
Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.Following examples for illustration of the present invention, but are not used for limiting the scope of the invention.
Embodiments provide the magnetic evaluation method that unrelieved stress effect is eliminated in a kind of post weld heat treatment, as shown in Figure 1, comprising:
According to micro-magnetic signal in region to be evaluated before the thermal treatment of default collection path measurements, and record gather micro-magnetic signal H
pand corresponding check point position X, with obtain the first peak peak value H of the micro-magnetic signal of collection
p-p1with the first greatest gradient value
In previous step, X place, check point position gathers micro-magnetic signal H in region to be evaluated after thermal treatment
p, with obtain the second peak-to-peak value H of the micro-magnetic signal of collection
p-p2with the second greatest gradient value
Calculate the second peak-to-peak value H
p-p2with first peak peak value H
p-p1peak-to-peak value reduction Δ H
p-p=H
p-p1-H
p-p2and the second greatest gradient value
with the first greatest gradient value
grad difference
to obtain peak-to-peak value reduction Δ H
p-p=H
p-p1-H
p-p2with first peak peak value H
p-p1the first ratio
and Grad difference
with the first greatest gradient value
the second ratio
Judge the first ratio λ
1with the second ratio λ
2whether accord with pre-conditioned, if meet pre-conditioned, after thermal treatment, the unrelieved stress in region to be evaluated is eliminated and is produced a desired effect.
The magnetic evaluation method of unrelieved stress effect is eliminated in the post weld heat treatment that the embodiment of the present invention provides, gather peak-to-peak value and the greatest gradient value of the unrelieved stress before and after thermal treatment respectively, can judge after processing whether the unrelieved stress of weldment after heat treatment around weld seam is effectively eliminated, thus avoid weldment not reach requirement and in use potential safety hazard because of the elimination of unrelieved stress after thermal treatment, there is realistic meaning and industry meaning.Evaluation method result of the present invention is accurate, and testing process is effective, simple to operate fast.
By ensureing the accuracy of institute's micro-magnetic signal of collections, alternatively, in the embodiment of the present invention, default collection path orthogonal is in weld seam, and extends to this weld seam both sides predeterminable range respectively.Namely signals collecting path arranges one at a certain distance along bead direction, and every bar presets the both sides extension predeterminable range of collection path respectively to weld seam.Alternatively, this predeterminable range is 100mm.Micro-magnetic signal can be detected fast like this, emergency situations can be avoided in testing process the impact of testing result, thus improve the accuracy of testing result.
By improve further the accuracy of the micro-magnetic signal of collection, the embodiment of the present invention is 0.5mm ~ 1mm in the collection step-length of the micro-magnetic signal gathering the region to be evaluated before and after thermal treatment.Can avoid that step-length is excessive causes the consequence that gathered micro-magnetic signal is inaccurate or do not collect by reducing to gather step-length, making the first peak peak value H of detection
p-p1with the second peak-to-peak value H
p-p2more accurate.
Alternatively, judge whether the first ratio and the second ratio accord with pre-conditioned, if meet pre-conditioned, after thermal treatment, region to be evaluated has been eliminated in the step of unrelieved stress, is pre-conditionedly:
The curve of micro-magnetic signal in the region to be evaluated after thermal treatment tends to level, the first ratio >=50% and the second ratio >=50%.
Alternatively, the curve of micro-magnetic signal in the region to be evaluated after thermal treatment tends to the following formula of horizontal demand fulfillment:
dH
2/dx≤3(A/m)/mm。
The superiority of unrelieved stress appraisal procedure is eliminated in the post weld heat treatment provided for fully demonstrating the embodiment of the present invention, and as shown in table 1, the present invention is further described this appraisal procedure in conjunction with welded plate and welded tube part, Fig. 2 ~ Fig. 3 and table 1 ~ table 3.
Table 1 running parameter table
| Welded plate 1# | Welded tube part 2# | |
| Material | Q235B | 20# |
| Specification (mm) | 280×260×14 | Φ195×8 |
| Detect path | 2-1、2-2、2-3 | 3-1、3-2、3-3 |
Fig. 2 is that the welded plate adopted in one embodiment of the invention presets detection path profile.With reference to Fig. 2, in one embodiment of the invention, unrelieved stress before and after welded plate 20 thermal treatment of Q235B type is detected, get three default detection paths perpendicular to bead direction along weld seam 21, namely preset and detect path 2-1, preset to detect path 2-2 and preset and detect path 2-3.Preset detection path along three respectively to carry out measuring micro-magnetic signal H
p, collection step-length is 1mm, and records the micro-magnetic signal H gathered
pwith this micro-magnetic signal H
pcorresponding check point position X (as obtain in Fig. 2 X1 ..., Xm).
Preset the micro-magnetic signal gathered before and after the thermal treatment of path collection welded plate according to every bar, the micro-magnetic signal before thermal treatment is designated as H
1, H
2, and calculate the first peak peak value H that every bar presets micro-magnetic signal of the distortion gathering passage zone
p-p1with the first greatest gradient value
second peak-to-peak value H
p-p2with the second greatest gradient value
Calculate the second peak-to-peak value H
p-p2with first peak peak value H
p-p1peak-to-peak value reduction Δ H
p-p=H
p-p1-H
p-p2and the second greatest gradient value
with the first greatest gradient value
grad difference
to obtain peak-to-peak value reduction Δ H
p-p=H
p-p1-H
p-p2with first peak peak value H
p-p1the first ratio
and Grad difference
with the first greatest gradient value
the second ratio
As shown in table 2 to the detection data before and after this welded plate thermal treatment.
The testing result of table 2 welded plate
| Path | Hp-p1 | Hp-p2 | dH1/dx | dH2/dx | ΔHp-p1 | ΔdH1/dx | λ 1 | λ 2 |
| 2-1 | 75 | 16 | 6 | 2 | 59 | 4 | 78.7％ | 66.7％ |
| 2-2 | 152 | 12 | 10 | 2 | 140 | 8 | 92.1％ | 80.0％ |
| 2-3 | 210 | 26 | 15 | 3 | 184 | 12 | 87.6％ | 80.0％ |
Note: H
p-p1with H
p-p2, unit A/m; DH
1/ dx and dH
2/ dx, unit: (A/m)/mm.
In the embodiment of the present invention, dH after three default detection path thermal treatments
2/ dx is respectively 2,2 and 3, the first ratio λ
1be respectively 78.7%, 92.1%, 87.6%, the second ratio λ
2be respectively 66.7%, 80.0%, 80.0%, meet pre-conditioned requirement, after this thermal treatment is described, region to be evaluated reaches the requirement that unrelieved stress is eliminated.
In another embodiment of the present invention, as shown in table 1 and Fig. 3, employing diameter is the welded tube part 30 of Φ 195mm, three default collection paths perpendicular to weld seam 31 are got in direction along weld seam 31 respectively, preset as shown in Figure 3 to gather path 3-1, the default path 3-2 of collection and preset to gather path 3-3.The magnetic evaluation method that unrelieved stress effect is eliminated in the post weld heat treatment adopting the embodiment of the present invention to provide detects, and after three detection path thermal treatments, dH/dx is respectively 2,2,2, λ
1be respectively 65.8%, 50.0%, 81.8%, λ
2be respectively 50.0%, 66.7,60.0%, meet pre-conditioned requirement, after this thermal treatment is described, region to be evaluated reaches the requirement that unrelieved stress is eliminated.
The testing result of table 3 welded tube part
Note: H
p-p1with H
p-p2, unit A/m; DH
1/ dx and dH
2/ dx, unit: (A/m)/mm.
It should be noted that, the post weld heat treatment of whole piece weld seam is eliminated to the effect assessment of welding residual stress, at least three different evaluation regions should be selected on fusion length direction to be evaluated to evaluate according to above-mentioned flow process, only have the post weld heat treatment in all regions to be evaluated disappear residual effect fruit evaluation result be qualified, could assert whole piece weld seam post weld heat treatment elimination welding residual stress effect reach re-set target.
In sum, the magnetic evaluation method of unrelieved stress effect is eliminated in the post weld heat treatment that the embodiment of the present invention provides, gather peak-to-peak value and the greatest gradient value of the unrelieved stress before and after thermal treatment respectively, can judge after processing whether the unrelieved stress of weldment after heat treatment around weld seam is effectively eliminated, thus avoid weldment because not reaching the requirement and in use potential safety hazard of eliminating unrelieved stress after thermal treatment, there is realistic meaning and industry meaning.Evaluation method result of the present invention is accurate, and testing process is effective, simple to operate fast.
In the present invention, term " first ", " second ", " the 3rd " only for describing object, and can not be interpreted as instruction or hint relative importance.Term " multiple " refers to two or more, unless otherwise clear and definite restriction.
Although describe embodiments of the present invention by reference to the accompanying drawings, but those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, such amendment and modification all fall into by within claims limited range.
Claims (7)
1. a magnetic evaluation method for unrelieved stress effect is eliminated in post weld heat treatment, it is characterized in that, comprising:
According to micro-magnetic signal in region to be evaluated before the thermal treatment of default collection path measurements, and record gather micro-magnetic signal and corresponding check point position, with obtain the first peak peak value of the micro-magnetic signal of collection and the first greatest gradient value;
Gather micro-magnetic signal in region to be evaluated after thermal treatment according to check point position in previous step, identical default collection path, with obtain the second peak-to-peak value of the micro-magnetic signal of collection and the second greatest gradient value;
Calculate the peak-to-peak value reduction of described second peak-to-peak value and described first peak peak value and the Grad difference of described second greatest gradient value and described first greatest gradient value, with the second ratio of the first ratio and described Grad difference and described first greatest gradient value that obtain described peak-to-peak value reduction and described first peak peak value;
Judge whether described first ratio and described second ratio accord with pre-conditioned, if meet pre-conditioned, after thermal treatment, the welding residual stress in region to be evaluated produces a desired effect.
2. the magnetic evaluation method of unrelieved stress effect is eliminated in post weld heat treatment according to claim 1, and it is characterized in that, described default collection path orthogonal in weld seam, and extends to this weld seam both sides predeterminable range respectively.
3. the magnetic evaluation method of unrelieved stress effect is eliminated in post weld heat treatment according to claim 2, it is characterized in that, described predeterminable range be weld width, weld seam zone of influence width and redundant wide and.
4. the magnetic evaluation method of unrelieved stress effect is eliminated in post weld heat treatment according to claim 3, and it is characterized in that, described predeterminable range is 100mm.
5. the magnetic evaluation method of unrelieved stress effect is eliminated in post weld heat treatment according to claim 1, it is characterized in that, the collection step-length gathering micro-magnetic signal in the region to be evaluated before and after thermal treatment is 0.5mm ~ 1mm.
6. the magnetic evaluation method of unrelieved stress effect is eliminated in post weld heat treatment according to claim 1, it is characterized in that, describedly judge whether described first ratio and described second ratio accord with pre-conditioned, if meet pre-conditioned, after thermal treatment, region to be evaluated has been eliminated in the step of unrelieved stress, is describedly pre-conditionedly:
The curve of micro-magnetic signal in the region to be evaluated after thermal treatment tends to level, the first ratio >=50% and the second ratio >=50%.
7. the magnetic evaluation method of unrelieved stress effect is eliminated in post weld heat treatment according to claim 6, and it is characterized in that, the curve of micro-magnetic signal in the region to be evaluated after described thermal treatment tends to the following formula of horizontal demand fulfillment:
dH
2/dx≤3(A/m)/mm。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510580478.0A CN105203625B (en) | 2015-09-11 | 2015-09-11 | The magnetic evaluation method of post weld heat treatment elimination residual stress effect |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510580478.0A CN105203625B (en) | 2015-09-11 | 2015-09-11 | The magnetic evaluation method of post weld heat treatment elimination residual stress effect |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105203625A true CN105203625A (en) | 2015-12-30 |
| CN105203625B CN105203625B (en) | 2018-12-04 |
Family
ID=54951416
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510580478.0A Active CN105203625B (en) | 2015-09-11 | 2015-09-11 | The magnetic evaluation method of post weld heat treatment elimination residual stress effect |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105203625B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115906555A (en) * | 2022-10-12 | 2023-04-04 | 中建二局安装工程有限公司 | COMSOL-based prediction method for residual stress and leakage magnetic field thereof in welding process |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5461982A (en) * | 1977-10-27 | 1979-05-18 | Toshiba Corp | Evaluation method of sensitization by electrochemical techniques of steel materials |
| JPH09234585A (en) * | 1996-02-29 | 1997-09-09 | Mitsubishi Heavy Ind Ltd | Welding equipment with welding residual stress reducing equipment |
| CN1374508A (en) * | 2002-04-05 | 2002-10-16 | 西安交通大学 | Evaluation system of visible deformation as residual welding stress eliminating effect |
| CN101210904A (en) * | 2006-12-28 | 2008-07-02 | 上海宝钢工业检测公司 | Metal magnetic memory rapid previewing method |
| CN104897320A (en) * | 2015-06-16 | 2015-09-09 | 黄小莲 | Method for measuring welding residual stress |
-
2015
- 2015-09-11 CN CN201510580478.0A patent/CN105203625B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5461982A (en) * | 1977-10-27 | 1979-05-18 | Toshiba Corp | Evaluation method of sensitization by electrochemical techniques of steel materials |
| JPH09234585A (en) * | 1996-02-29 | 1997-09-09 | Mitsubishi Heavy Ind Ltd | Welding equipment with welding residual stress reducing equipment |
| CN1374508A (en) * | 2002-04-05 | 2002-10-16 | 西安交通大学 | Evaluation system of visible deformation as residual welding stress eliminating effect |
| CN101210904A (en) * | 2006-12-28 | 2008-07-02 | 上海宝钢工业检测公司 | Metal magnetic memory rapid previewing method |
| CN104897320A (en) * | 2015-06-16 | 2015-09-09 | 黄小莲 | Method for measuring welding residual stress |
Non-Patent Citations (3)
| Title |
|---|
| 邢海燕 等: "拉压载荷下焊缝的磁记忆表征及热处理评价", 《大庆石油学院学报》 * |
| 邸新杰 等: "焊接裂纹的金属磁记忆定量化评价研究", 《材料工程》 * |
| 郭奇 等: "磁记忆技术在焊缝缺陷检测中的量化研究", 《焊接技术》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115906555A (en) * | 2022-10-12 | 2023-04-04 | 中建二局安装工程有限公司 | COMSOL-based prediction method for residual stress and leakage magnetic field thereof in welding process |
| CN115906555B (en) * | 2022-10-12 | 2023-09-19 | 中建二局安装工程有限公司 | Residual stress and leakage magnetic field prediction method in welding process based on COMSOL |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105203625B (en) | 2018-12-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104931576B (en) | A kind of characterizing method of weld crack expansion process | |
| CN105203635A (en) | Surface wave detection method for longitudinal defect on outer surface of small-diameter tube | |
| JP2015513371A (en) | Method for manufacturing a welded tube from steel | |
| Hosseinzadeh et al. | Slitting and contour method residual stress measurements in an edge welded beam | |
| CN108072337B (en) | Method for measuring object defect depth under condition of considering defect size | |
| US10416022B2 (en) | Apparatus and method for monitoring water level within pipe | |
| Prajapati et al. | Potential drop detection of creep damage in the vicinity of welds | |
| CN109307568A (en) | The lossless detection method of welding residual stress and the probe for using this method | |
| CN103149277A (en) | Phased array ultrasound detecting scanning path optimizing method based on defect detection rate | |
| CN105203625A (en) | Magnetic evaluation method for residual stress relieving effect in postweld heat treatment | |
| CN105351322A (en) | Test block for bolt ultrasonic testing and bolt ultrasonic testing method and device | |
| CN103870679A (en) | Judgment method for minimum inserting section size in Charpy impact test sample recombination technology | |
| CN104713949B (en) | A kind of ultrasonic detection method for reinforcing bar full penetration weld | |
| CN106872585A (en) | A kind of wheel blank axial ultrasonic wave inspection surface compensation method | |
| Li | Modeling and on-line estimation of electrode wear in resistance spot welding | |
| JP6015295B2 (en) | Heat treatment method for ERW welded pipe | |
| CN203894200U (en) | Reference block for ultrasonic detection of nickel base alloy weld | |
| CN105891210A (en) | Method for detecting fatigue life of resistance welding point | |
| CN105312770A (en) | Laser welding mode determination method based on plasma electric signals | |
| CN104374834A (en) | Sensitivity adjusting method of ultrasonic testing flaw detector and ultrasonic testing flaw detection method | |
| CN103592366A (en) | Method for detecting ultrasonic flaw detection | |
| CN108169326A (en) | Thick-wall tube inner surface cracks buried depth supersonic detection method | |
| CN211783233U (en) | Brake caliper support pin hole depth gauge | |
| CN102706745A (en) | Welding strength detection method | |
| JP6347307B2 (en) | Steel pipe deformation performance evaluation method, steel pipe manufacturing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220414 Address after: Rooms 601, 602, 603, 605 and 608, 6 / F, No. 28, North Third Ring East Road, Chaoyang District, Beijing 100020 Patentee after: ZHONGTE Inspection Group Co.,Ltd. Address before: 100013 building, building 2, Heping Street, Beijing, Xiyuan, Chaoyang District Patentee before: CHINA SPECIAL EQUIPMENT INSPECTION AND Research Institute |
|
| TR01 | Transfer of patent right |