CN102608169A - Method for determining precision of blind-hole method residual stress testing system - Google Patents
Method for determining precision of blind-hole method residual stress testing system Download PDFInfo
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- CN102608169A CN102608169A CN201210051629XA CN201210051629A CN102608169A CN 102608169 A CN102608169 A CN 102608169A CN 201210051629X A CN201210051629X A CN 201210051629XA CN 201210051629 A CN201210051629 A CN 201210051629A CN 102608169 A CN102608169 A CN 102608169A
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Abstract
The invention belongs to the technical field of precision determination, and relates to a method for determining the precision of a blind-hole method residual stress testing system. The method comprises the specific technologies of sample plate sampling, stress-relieving annealing, sample surface preparing and strain gauge adhering, data line connection, testing parameter configuring, hole drilling, data collecting, data processing, and precision determining. The method is advantaged in stable technology and accurate result. With the method, deviations of a testing system can be visually, rapidly, and quantitatively determined. Therefore, testing errors caused by influencing factors such as strain gauge quality, hole drilling eccentricity, and additional strain can be conveniently adjusted. Thus, the accuracy of the residual stress testing before and after hot rolled coil decoiling can be ensured.
Description
Technical field
The invention belongs to the precision determination technical field, particularly a kind of method of measuring blind hole method unrelieved stress test macro precision.
Background technology
Hot-rolled sheet coil is calmed down behind the chi " back of a bow " that often occurs, " wooden dipper is bent " phenomenon opening.Its reason mainly is the inequality of plate upper and lower surfaces (inside surface outside the coiled sheet) plastic yield in opening flat process and import unrelieved stress and cause.Too big unrelieved stress and unreasonable distribution thereof will cause steel plate to locate machinery/flame cutting back camber of sheet or distortion and can't use the user.Through blind hole method test and analyze open flat before and after the regularity of distribution of unrelieved stress of roll bending, the hot-rolled coil that can be different steel grade different size different process is formulated the comparatively perfect flat technology of opening provides direct data support.
But, for blind hole method test unrelieved stress, because its influence factor is many; The quality of paster, the degree of eccentricity of boring, additional strain etc. are all influential to test result; When particularly adopting electric drill to hole, influence factors such as the additional strain that in boring procedure, produces, boring off-centre are very big to the influence of test result, and the relative electric drill punching of high speed pneumatic drill; Precision is high a lot, but can't learn the accuracy of its measurement equally.
Still there is not at present the precision that clear and definite standard and method are verified blind hole method unrelieved stress test macro in the world; Chinese vessel industry standard CB 3395 and American society association criterion ASTM E 837 are the minimizing experimental error; Hole off-centre and the plastic yield of limit, hole there are concrete modification method within the specific limits, but how the precision of whole blind hole method unrelieved stress test macro is evaluated not specified (NS).The present invention is directed to the blind hole method unrelieved stress test calibration of test macro precision before, propose a kind of method of measuring blind hole method unrelieved stress test macro precision.
Summary of the invention
The object of the present invention is to provide a kind of method of measuring blind hole method unrelieved stress test macro precision.In the certain experience value, can think that the precision of this test macro is higher, can directly carry out the actual samples board test.The test macro precision surpasses the certain experience value, thinks that then the error of test macro is bigger than normal, earlier Correlative Influence Factors is adjusted and is revised, and error is less than carrying out the actual samples board test after the empirical value again.
The concrete processing step of the present invention is following:
(1) sample board sampling: select a bulk matter and thickness with the consistent sample board of actual test board, planar dimension is not less than 150mm * 150mm, is as the criterion can put into heat-treatment furnace.
(2) stress relief annealing: sample board is put into heat-treatment furnace, be heated to following 50-150 ℃ of sample board material eutectoid temperature (Ac1) with stove, temperature retention time 1-3h cools to room temperature with the furnace.
(3) stickup of specimen surface preparation and foil gauge: on annealed sheet, select 3-10 test point, the test point surface of position is polished and cleaned,, and solidify more than 6 hours then at point position stickup foil gauge.When pasting foil gauge, the foil gauge spacing is greater than 15D
0, D wherein
0Bit diameter for drilling equipment.
(4) link of data line: with electric soldering iron with lead and foil gauge wire bonds on connection terminal, connect the line on the strain-recording instrument then.
(5) test parameters setting:,, comprise channel selecting, electric bridge selection, the input of sensitivity coefficient (K), zeroing, entering test data sheet state in the enterprising line parameter setting of strain-recording instrument according to testing requirements.
(6) boring: drilling equipment is fixed on the sample board, and aims at the foil gauge center and punch, the degree of depth in hole and the ratio of diameter are controlled between the 1.0-1.2.
(7) collection of data: the strain value that discharges in the test is noted through strain-recording instrument.
(8) processing of data: correlation formula (1)-(5) according among the Chinese vessel industry standard CB 3395 calculate unrelieved stress.
(9) confirming of precision: the unrelieved stress of annealed sheet is regarded as zero, then this annealed sheet is carried out unrelieved stress and test the precision that the maximum zero error that obtains is this batch test macro.
The invention has the advantages that:
(1) use annealed sheet as test material, draw materials conveniently, thermal treatment is simple, the unrelieved stress of test board is very little after the stress relief annealing, and myopia is zero, and reliability is high.
(2) with the maximum zero error of annealed sheet unrelieved stress test as system accuracy, precision that can quantitative response blind hole method unrelieved stress test macro.Open the unrelieved stress test of flat front and back for hot-rolled high-strength steel plate precise and stable system accuracy is provided; For the accurate high-strength plate unrelieved stress of test provides direct data support, make high strength steel plate since unrelieved stress that the aligning process imports and unreasonable distribution thereof cause steel plate the user locate machinery/flame cutting back camber of sheet or distortion and situation about can't use be improved significantly.
Description of drawings
Fig. 1 reaches the synoptic diagram of on annealed sheet, selecting test point for the annealed sheet sampling.
Fig. 2 is the synoptic diagram of foil gauge.Wherein, R1, R2, R3 are three groups of strain grid on the foil gauge.
The schematic flow sheet of Fig. 3 test process.
Fig. 4 residual stress distribution figure that test obtains to annealed sheet.Wherein, σ
xThe size of expression rolling direction unrelieved stress, σ
yThe size of expression Width unrelieved stress.
Embodiment
Embodiment 1
A kind of method of measuring blind hole method unrelieved stress test macro precision, it comprises following steps:
1) sample board sampling: getting a thickness is 8mm, is of a size of certain high strength steel plate of 400mm * 200mm.
2) stress relief annealing: present embodiment adopts and slowly is heated to 650 ℃ with stove, and insulation 2h cools to room temperature then with the furnace.
3) stickup of specimen surface preparation and foil gauge: every at a distance from 1 test point of 50mm layout on the annealed sheet of long 400mm, arrange 7 test points altogether; To polishing and clean in the point position surface, paste foil gauge at point position subsequently, and solidified 18 hours.
4) link of data line: with electric soldering iron with lead and foil gauge wire bonds on connection terminal, connect the line on the strain-recording instrument then.
5) test parameters setting:,, comprise channel selecting, electric bridge selection, the input of sensitivity coefficient (K), zeroing, entering test data sheet state in the enterprising line parameter setting of strain-recording instrument according to testing requirements.
6) boring: present embodiment adopts the high speed pneumatic drill to hole, and drilling equipment is fixed on the sample board, aims at the foil gauge center and punches, and the degree of depth in hole and the ratio of diameter are 1.1.
7) collection of data: the strain value that discharges in the test is noted through strain-recording instrument.
8) processing of data: formula (1)-(5) according among the Chinese vessel industry standard CB 3395 calculate unrelieved stress.
9) confirming of precision: in the present embodiment; Unrelieved stress size and distribution plan to after the annealed sheet test are seen table 1 and Fig. 4; The maximum zero error of 7 the horizontal longitudinal direction unrelieved stress sizes of point of surveying is-11MPa that promptly the precision of this batch unrelieved stress test macro is ± 11MPa.
Because the influence of factors such as paster quality, boring degree of eccentricity, additional strain unavoidably can produce certain measuring errors in the test process in the experimentation.Abundant residues stress test data according to hot rolled steel plate is carried out show; Generally adopt unrelieved stress that the boring of high speed pneumatic drill obtains in ± 20MPa to annealed sheet; Adopt residual-stress value that electric drill boring obtains in ± 40MPa; Can think that the test macro precision is higher, can directly test the actual samples plate; Surpass empirical value if annealed sheet is recorded residual-stress value, can each influence factor such as paster quality, boring degree of eccentricity, additional strain be improved and adjust, test once more according to the actual conditions in the test process.General recommendations adopts the high speed pneumatic drill to hole, and its boring degree of eccentricity is much little with the relative electric drill of boring additional strain, and the precision of test macro is higher relatively.Test result is as shown in table 1, and positive number is represented tension, the negative number representation compressive stress.
Table 1 annealed sheet unrelieved stress test result
| Measuring point distance (mm) | 50 | 100 | 150 | 200 | 250 | 300 | 350 |
| σ x(MPa) | -0.2 | 10.8 | 2.0 | -8.8 | -10.2 | 2.0 | -6.4 |
| σ y(MPa) | -11.0 | 7.5 | -2.0 | -9.5 | -10.9 | -2.0 | -7.7 |
Claims (3)
1. method of measuring blind hole method unrelieved stress test macro precision is characterized in that processing step is:
(1) sample board sampling: select a thickness to approach the sample board of actual test board, planar dimension is not less than 150mm * 150mm, is as the criterion can put into heat-treatment furnace;
(2) stress relief annealing: sample board is put into heat-treatment furnace, be heated to following 50-150 ℃ of sample board material eutectoid temperature with stove, temperature retention time 1-3h cools to room temperature with the furnace;
(3) stickup of specimen surface preparation and foil gauge: on annealed sheet, select 3-10 measuring point, to polishing and clean in the point position surface, at point position stickup foil gauge;
(4) link of data line: with electric soldering iron with lead and foil gauge wire bonds on connection terminal, connect the line on the strain-recording instrument then;
(5) test parameters setting:,, comprise channel selecting, electric bridge selection, the input of sensitivity coefficient, zeroing, entering test data sheet state in the enterprising line parameter setting of strain-recording instrument according to testing requirements;
(6) boring: drilling equipment is fixed on the sample board, and aims at the foil gauge center and punch, the degree of depth in hole and the ratio of diameter are 1.0-1.2;
(7) collection of data: the strain value that discharges in the test is noted through strain-recording instrument;
(8) processing of data: the correlation formula according among the Chinese vessel industry standard CB 3395 calculates unrelieved stress;
(9) confirming of precision: the unrelieved stress of annealed sheet is regarded as zero, this annealed sheet is carried out unrelieved stress test the precision that the maximum zero error that obtains is this batch test macro.
2. method according to claim 1 is characterized in that, be more than 6 hours the set time after foil gauge is pasted in the step (3).
3. method according to claim 1 is characterized in that, step (3) foil gauge spacing is greater than 15D
0, D
0Bit diameter for drilling equipment.
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Cited By (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102853952A (en) * | 2012-09-18 | 2013-01-02 | 哈尔滨电机厂有限责任公司 | Method for testing welding residual stress of mixed-flow turning wheel |
| CN103042072A (en) * | 2012-12-24 | 2013-04-17 | 燕山大学 | Method for predicting hot-rolling coiling stress and inter-layer slippage based on spiral opening barrel shape |
| CN104406717A (en) * | 2014-12-23 | 2015-03-11 | 内蒙古包钢钢联股份有限公司 | Method for testing stress on blast furnace shell |
| CN104458067A (en) * | 2014-12-23 | 2015-03-25 | 内蒙古包钢钢联股份有限公司 | H-shaped steel bending residual stress detecting method |
| CN104458078A (en) * | 2014-12-23 | 2015-03-25 | 内蒙古包钢钢联股份有限公司 | H-shaped steel lateral residual stress detecting method |
| CN104458070A (en) * | 2014-12-23 | 2015-03-25 | 内蒙古包钢钢联股份有限公司 | Patch method for detecting transverse residual stress of H-section steel |
| CN104483047A (en) * | 2014-12-23 | 2015-04-01 | 内蒙古包钢钢联股份有限公司 | Surface-mounting method for testing residual bending stress of H-shaped steel |
| CN105784216A (en) * | 2016-03-07 | 2016-07-20 | 杭州华新检测技术股份有限公司 | Detecting method for residual stress of steel structure |
| CN105841854A (en) * | 2016-04-28 | 2016-08-10 | 西南石油大学 | Welding residual stress testing method |
| CN107036744A (en) * | 2016-12-30 | 2017-08-11 | 西北工业大学 | A kind of residual stress blind hole method of testing |
| CN107677403A (en) * | 2017-08-29 | 2018-02-09 | 芜湖市风蝉电竞文化传媒有限公司 | A kind of residual stress blind hole detection method |
| CN108168761A (en) * | 2018-02-11 | 2018-06-15 | 中铝材料应用研究院有限公司 | A kind of method based on residual stress release amount of warpage prediction sheet metal residual stress |
| CN108181032A (en) * | 2017-12-21 | 2018-06-19 | 重庆市铜梁区华亿来铝材加工厂 | A kind of residual stress detection method |
| CN109781323A (en) * | 2018-11-30 | 2019-05-21 | 华东交通大学 | The method for detecting rail bottom residual stress after Switch quenching based on stress release theory |
| CN109799020A (en) * | 2019-02-19 | 2019-05-24 | 中国石油大学(华东) | It is a kind of can manufacture on-the-spot test welding residual stress method |
| CN110865097A (en) * | 2019-10-23 | 2020-03-06 | 上海建工四建集团有限公司 | Sensor for monitoring surface layer falling and application method thereof |
| CN111521312A (en) * | 2020-05-08 | 2020-08-11 | 中国工程物理研究院化工材料研究所 | Method for calibrating residual stress of optical fiber measurement material based on blind hole method |
| CN111855057A (en) * | 2020-07-27 | 2020-10-30 | 大连理工大学 | Method for measuring residual stress distribution of composite material plate based on blind hole method |
| CN112036059A (en) * | 2020-07-30 | 2020-12-04 | 中冶建筑研究总院有限公司 | Method for detecting working stress based on blind hole method |
| CN112857638A (en) * | 2020-12-25 | 2021-05-28 | 湖南应用技术学院 | Drilling internal stress measurement equipment and measurement method thereof |
| CN112924065A (en) * | 2021-01-25 | 2021-06-08 | 华南理工大学 | Measuring method for measuring residual stress of curved surface based on blind hole method |
| CN113295327A (en) * | 2020-02-21 | 2021-08-24 | 中国石油天然气集团有限公司 | Zero-stress sample for ultrasonic stress measurement method and preparation method thereof |
| CN114894356A (en) * | 2022-04-24 | 2022-08-12 | 南京华建检测技术有限公司 | Method and device for detecting residual stress of welding seam of steel structure bridge by ultrasonic time difference method |
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| CN102853952A (en) * | 2012-09-18 | 2013-01-02 | 哈尔滨电机厂有限责任公司 | Method for testing welding residual stress of mixed-flow turning wheel |
| CN103042072A (en) * | 2012-12-24 | 2013-04-17 | 燕山大学 | Method for predicting hot-rolling coiling stress and inter-layer slippage based on spiral opening barrel shape |
| CN104483047A (en) * | 2014-12-23 | 2015-04-01 | 内蒙古包钢钢联股份有限公司 | Surface-mounting method for testing residual bending stress of H-shaped steel |
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| CN104458078A (en) * | 2014-12-23 | 2015-03-25 | 内蒙古包钢钢联股份有限公司 | H-shaped steel lateral residual stress detecting method |
| CN104458070A (en) * | 2014-12-23 | 2015-03-25 | 内蒙古包钢钢联股份有限公司 | Patch method for detecting transverse residual stress of H-section steel |
| CN104406717A (en) * | 2014-12-23 | 2015-03-11 | 内蒙古包钢钢联股份有限公司 | Method for testing stress on blast furnace shell |
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| CN107036744A (en) * | 2016-12-30 | 2017-08-11 | 西北工业大学 | A kind of residual stress blind hole method of testing |
| CN107036744B (en) * | 2016-12-30 | 2020-05-15 | 西北工业大学 | Residual stress blind hole testing method |
| CN107677403A (en) * | 2017-08-29 | 2018-02-09 | 芜湖市风蝉电竞文化传媒有限公司 | A kind of residual stress blind hole detection method |
| CN108181032A (en) * | 2017-12-21 | 2018-06-19 | 重庆市铜梁区华亿来铝材加工厂 | A kind of residual stress detection method |
| CN108168761A (en) * | 2018-02-11 | 2018-06-15 | 中铝材料应用研究院有限公司 | A kind of method based on residual stress release amount of warpage prediction sheet metal residual stress |
| CN109781323A (en) * | 2018-11-30 | 2019-05-21 | 华东交通大学 | The method for detecting rail bottom residual stress after Switch quenching based on stress release theory |
| CN109799020A (en) * | 2019-02-19 | 2019-05-24 | 中国石油大学(华东) | It is a kind of can manufacture on-the-spot test welding residual stress method |
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| CN113295327A (en) * | 2020-02-21 | 2021-08-24 | 中国石油天然气集团有限公司 | Zero-stress sample for ultrasonic stress measurement method and preparation method thereof |
| CN111521312A (en) * | 2020-05-08 | 2020-08-11 | 中国工程物理研究院化工材料研究所 | Method for calibrating residual stress of optical fiber measurement material based on blind hole method |
| CN111855057A (en) * | 2020-07-27 | 2020-10-30 | 大连理工大学 | Method for measuring residual stress distribution of composite material plate based on blind hole method |
| CN112036059A (en) * | 2020-07-30 | 2020-12-04 | 中冶建筑研究总院有限公司 | Method for detecting working stress based on blind hole method |
| CN112036059B (en) * | 2020-07-30 | 2023-12-15 | 中冶建筑研究总院有限公司 | Method for detecting working stress based on blind hole method |
| CN112857638A (en) * | 2020-12-25 | 2021-05-28 | 湖南应用技术学院 | Drilling internal stress measurement equipment and measurement method thereof |
| CN112857638B (en) * | 2020-12-25 | 2022-05-17 | 湖南应用技术学院 | Drilling internal stress measurement equipment and measurement method thereof |
| CN112924065A (en) * | 2021-01-25 | 2021-06-08 | 华南理工大学 | Measuring method for measuring residual stress of curved surface based on blind hole method |
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Application publication date: 20120725 |