CN101738371B - Method for assessing thermotolerance of cold rolling silicon steel insulation coating - Google Patents
Method for assessing thermotolerance of cold rolling silicon steel insulation coating Download PDFInfo
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- CN101738371B CN101738371B CN2008102289472A CN200810228947A CN101738371B CN 101738371 B CN101738371 B CN 101738371B CN 2008102289472 A CN2008102289472 A CN 2008102289472A CN 200810228947 A CN200810228947 A CN 200810228947A CN 101738371 B CN101738371 B CN 101738371B
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Abstract
The invention discloses a method for assessing thermotolerance of cold rolling silicon steel insulation coating. The method mainly comprises sampling, thermotolerance annealing, and observing the surface of the sample after annealing, and is characterized in that the sample is subject to interlayer resistance and adhesiveness test before annealing, the sample satisfying the conditions is put into an annealing furnace for annealing, the surface of the sample is observed after annealing, if the surface of the sample taken out of the furnace has obvious flaws, the sample is judged unqualified; if the surface of the sample taken out of the furnace has no obvious flaws, further test for interlayer resistance and adhesiveness is carried out on the sample, and the thermotolerance of the insulation coating is judged according to the test data. The invention solves the problems in the existing assessing method such as delayed feedback and lack of instructiveness, efficiently assesses the thermotolerance of different variety of insulation coatings, and provides a convenient and fast assessing standard for development and production adjustment of nsulation coating variety.
Description
Technical field
The present invention relates to the stable on heating method of inspection of a kind of insulating coating, the stable on heating evaluation method of specifically a kind of cold rolled silicon steel insulating coating.
Background technology
Cold rolled silicon steel as the iron core of various motors and transformer, is an indispensable important magnetically soft alloy in electric power, electronics and the war industry mainly, requires power consumption few, and volume is little and in light weight.So the cold rolled silicon steel steel plate is except possessing steel conventional tensile strength, yield strength, extensibility; Outside the performance requirements such as the iron loss of silicon steel and magnetic strength, also require surface of steel plate smooth, smooth; Has the good insulation performance coated film.
Increase eddy current loss for preventing to be short-circuited between core lamination stack; The cold rolled silicon steel surface of steel plate often is coated with one deck insulation film; Generally do not need to be coated with again insullac after user's punching; When having only the higher insulativity of the above big power transformer requirement of above big generator of 100,000 KW or 100,000 KVA, on this dielectric film, can be coated with insullac again.
Wherein important one is good heat resistance to the requirement of insulating coating (film), when 750～820 ℃ of stress relief annealing, can not be destroyed.Because cold-reduced silicon sheet is in process such as shearing, punching press, bending, because mechanical stress and strain cause electromagnetic performance to worsen, its deterioration degree subtracts narrow and obvious increase with the punching width.In order to recover the original electromagnetic performance of punching material, after the punching bending machining, it is feasible adopting stress relief annealing.Through stress relief annealing, not only can reach the purpose of recovering original electromagnetic performance of material even raising, but also can reduce the burr and the planarization that improves material of punching.
So how the heat resistance of cold-rolled silicon steel coat need think better of and estimate.As cold rolled silicon steel manufacturing enterprise, the finished product cold rolled silicon steel that coating has been produced detects evaluation according to national standard or enterprises standard to relevant characters.Such as projects such as iron loss, magnetic strength, mechanical property, size, shape, surface check, insulating coating tack and interface resistance checks the special national standard and the method for inspection are arranged all, and also do not have the special method of inspection to unify with the national standard mode to cold rolled silicon steel insulating coating thermotolerance aspect.
All pay much attention to about the domestic and international same industry of silicon steel insulating coating, confidentiality is very strong, and mostly forms the proprietary technology raising market competitiveness of oneself.The most of employing of cold rolling non-orientation silicon steel coating contains sexavalent chrome half organic coating on the home market at present; This coating composition generally contains acryl resin or phenylpropyl alcohol-acrylic resin; Phosphate solution; Materials such as chromium trioxide, Posco2002 silicon steel patent abstract 100345726 patents are introduced this coating formula: coating composition is the MgO or the CaO of (percentage by weight) 6.00%～11.59%, 19.00%～24.59% CrO
3, 11.00%～15.74% emulsus acryl resin, 5%～8% monoethylene glycol, 0.01%～1% adjuvant, all the other are water.See that from result of use Chromium coating has the advantage that a lot of other coating can not be substituted: good rust-preventing characteristic, insulativity, heat-resisting quantity, weldability, outward appearance and the quality of turning blue, moderate cost.But the fatal shortcoming of Chromium coating is its toxicity; Sexavalent chrome in the coating material is the human body strong carcinogen; Though the advantage of this coated film is approved by domestic and international silicon steel manufacturer and user; But along with enhancing international, domestic popular environmental consciousness, containing hexavalent chromium coatings must be with stepping down from the stage of history.Think and satisfy the new demand of silicon steel coating that silicon steel manufacturing enterprise and scientific worker are in the research that does not contain sexavalent chrome silicon steel coating both at home and abroad.But see that from the kind that has appeared on the market quality is all barely satisfactory.Mainly show: also there is a big difference for rust-preventing characteristic, high temperature resistant and turning blue property aspect.
Data according to our grasp; Cold rolled silicon steel manufacturing enterprise is in coating variety development and ordinary production, and estimating insulating coating thermotolerance aspect does not have good measure and method, arrives the user to production marketing often; Use feedback to judge according to the user; The enterprise that has entrusts testing agency to detect thermotolerance, technical requirement be the sample steel band at 750 ℃, N
2Behind the protective atmosphere annealing insulation 2h, cool to 450 ℃ of 3h in air, be cooled to normal temperature, whether steel band is crooked on ф≤100mm pole, observe coating and come off.These evaluation methods not only the cycle long, follow the tracks of difficulty, feed back untimelyly, and some data deficiency directiveness is unfavorable for that cold rolled silicon steel manufacturing enterprise estimates and judges and produce and adjust.
Summary of the invention
The object of the present invention is to provide the stable on heating evaluation method of a kind of cold rolled silicon steel insulating coating; Judge the heat resistance of silicon steel steel plate insulating coating according to the data of sample detection before and after the annealing; Solve the problem that feedback is untimely and shortage is guiding that exists in the existing evaluation method, for the insulating coating variety development provides conveniently evaluation criterion with producing to adjust.
The objective of the invention is to realize like this; The stable on heating evaluation method of a kind of cold rolled silicon steel insulating coating mainly comprises sampling, heat-resisting annealing, specimen surface is observed in the back of annealing, and it is characterized in that, before the annealing sample is carried out interface resistance and tack detection; The sample that satisfies condition is put into annealing furnace anneals; Specimen surface is observed in the annealing back, if open defect appears in the specimen surface of coming out of the stove, then is judged to be defective; If come out of the stove the specimen surface no significant defect, then sample is carried out the further detection of interface resistance and tack, according to detecting data the thermotolerance of insulating coating is judged.
The stable on heating evaluation method of cold rolled silicon steel insulating coating of the present invention, the condition that sample satisfies before the annealing is: interface resistance>=200 Ω mm
2/ sheet, and tack is more than the A level; If the annealing back is the interface resistance>=70 Ω mm of the sample of coming out of the stove
2/ sheet, and tack is more than the D level, and the thermotolerance of insulating coating is qualified, otherwise is defective.Heat-resisting annealing process is: in the mixed atmosphere of nitrogen, hydrogen or nitrogen and hydrogen, carry out; Annealing temperature is controlled at 750～820 ℃, and annealing time is controlled at 2～2.5h; Being cooled to 40～60 ℃ stops the supple of gas or steam and comes out of the stove.
The present invention not only observes the surface state of steel plate sample after annealing; But also increased the interface resistance of steel plate sample and the detection of tack before and after the annealing; And judge silicon steel steel plate heat resistance according to the difference that detects data before and after the annealing; Solved the problem that the feedback that exists in the existing evaluation method is untimely and shortage is guiding; Passed judgment on the quality of insulating coating kind heat resistance effectively, possessed stronger directiveness and operability, for the insulating coating variety development provides conveniently evaluation criterion with producing to adjust.
Embodiment
With 6 kinds of stable on heating examples that verify as of cold rolled silicon steel insulating coating, evaluation method of the present invention is described further below.
Embodiment one
1, sampling: the steel plate size of sample is 300 * 100mm;
2, detect the interface resistance and the tack of steel plate sample before the annealing, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 381 Ω mm
2/ sheet;
Tack O level;
3, the heat-resisting annealing process of steel plate sample
Unit type: hydrogen (nitrogen) protection electric furnace;
Annealing way: 100% nitrogen; Atmosphere control mode: flowmeter control;
The annealing temperature time: 760 ± 5 ℃ * 2h;
The type of cooling: the water jacket natural cooling is cooled to 50 ℃ and stops the supple of gas or steam and come out of the stove;
120 ℃ begin ventilation, and 450 ℃ allow to shift onto cooling section, but forbid water flowing to be cooled off;
The experiment overall process definitely mustn't be stopped the supple of gas or steam, the operation of band gas, and sample is shifted cooling section onto must strengthen throughput, anti-oxidation, every cover sample must add backplate, simultaneously tighten;
4, carry out surface observation and Data Detection after the annealing
The back observation steel plate specimen surface of coming out of the stove does not have warpage, distortion, dirtyization; Coating does not have and comes off; The non-oxidation phenomenon;
Detect the interface resistance and the tack of annealing back steel plate sample, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 121 Ω mm
2/ sheet;
Tack A level;
5, estimate the thermotolerance result
Qualified.
Embodiment two
1, sampling: the steel plate size of sample is 300 * 100mm;
2, detect the interface resistance and the tack of steel plate sample before the annealing, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 376 Ω mm
2/ sheet;
Tack O level;
3, the heat-resisting annealing process of steel plate sample
Unit type: hydrogen (nitrogen) protection electric furnace;
Annealing way: 100% nitrogen, atmosphere control mode: flowmeter control;
The annealing temperature time: 780 ± 5 ℃ * 2.2h;
The type of cooling: the water jacket natural cooling is cooled to 50 ℃ and stops the supple of gas or steam and come out of the stove;
150 ℃ begin ventilation, and 400 ℃ allow to shift onto cooling section, but forbid water flowing to be cooled off;
The experiment overall process definitely mustn't be stopped the supple of gas or steam, the operation of band gas, and sample is shifted cooling section onto must strengthen throughput, anti-oxidation, every cover sample must add backplate, simultaneously tighten;
4, carry out surface observation and Data Detection after the annealing
The back observation steel plate specimen surface of coming out of the stove does not have warpage, distortion, dirtyization; Coating does not have and comes off; The non-oxidation phenomenon;
Detect the interface resistance and the tack of annealing back steel plate sample, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 136 Ω mm
2/ sheet;
Tack B level;
5, estimate the thermotolerance result
Qualified.
Embodiment three
1, sampling: the steel plate size of sample is 300 * 100mm;
2, detect the interface resistance and the tack of steel plate sample before the annealing, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 408 Ω mm
2/ sheet;
Tack A level;
3, the heat-resisting annealing process of steel plate sample
Unit type: hydrogen (nitrogen) protection electric furnace;
Annealing way: 100% nitrogen; Atmosphere control mode: flowmeter control;
The annealing temperature time: 780 ± 5 ℃ * 2.4h;
The type of cooling: the water jacket natural cooling is cooled to 40 ℃ and stops the supple of gas or steam and come out of the stove;
180 ℃ begin ventilation, and 480 ℃ allow to shift onto cooling section, but forbid water flowing to be cooled off;
The experiment overall process definitely mustn't be stopped the supple of gas or steam, the operation of band gas, and sample is shifted cooling section onto must strengthen throughput, anti-oxidation, every cover sample must add backplate, simultaneously tighten;
4, carry out surface observation and Data Detection after the annealing
The back observation steel plate specimen surface of coming out of the stove does not have warpage, distortion, dirtyization; Coating does not have and comes off; The non-oxidation phenomenon;
Detect the interface resistance and the tack of annealing back steel plate sample, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 151 Ω mm
2/ sheet;
Tack C level;
5, estimate the thermotolerance result
Qualified.
Embodiment four
1, sampling: the steel plate size of sample is 300 * 100mm;
2, detect the interface resistance and the tack of steel plate sample before the annealing, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 276 Ω mm
2/ sheet; Tack O level;
3, the heat-resisting annealing process of steel plate sample
Unit type: hydrogen (nitrogen) protection electric furnace;
Annealing way: 100% nitrogen, atmosphere control mode: flowmeter control;
The annealing temperature time: 810 ± 5 ℃ * 2h;
The type of cooling: the water jacket natural cooling is cooled to 60 ℃ and stops the supple of gas or steam and come out of the stove;
200 ℃ begin ventilation, and 500 ℃ allow to shift onto cooling section, but forbid water flowing to be cooled off;
The experiment overall process definitely mustn't be stopped the supple of gas or steam, the operation of band gas, and sample is shifted cooling section onto must strengthen throughput, anti-oxidation, every cover sample must add backplate, simultaneously tighten;
4, carry out surface observation and Data Detection after the annealing
The back observation steel plate specimen surface of coming out of the stove does not have warpage, distortion, dirtyization; Coating does not have and comes off; The non-oxidation phenomenon;
Detect the interface resistance and the tack of annealing back steel plate sample, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 95 Ω mm
2/ sheet;
Tack D level;
5, estimate the thermotolerance result
Qualified.
Embodiment five
1, sampling: the steel plate size of sample is 300 * 100mm;
2, detect the interface resistance and the tack of steel plate sample before the annealing, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 310 Ω mm
2/ sheet;
Tack O level;
3, the heat-resisting annealing process of steel plate sample
Unit type: hydrogen (nitrogen) protection electric furnace
Annealing way: 20% hydrogen+80% nitrogen, atmosphere control mode: flowmeter control;
The annealing temperature time: 800 ± 5 ℃ * 2h;
The type of cooling: the water jacket natural cooling is cooled to 50 ℃ and stops the supple of gas or steam and come out of the stove;
200 ℃ begin ventilation, and 500 ℃ allow to shift onto cooling section, but forbid water flowing to be cooled off;
The experiment overall process definitely mustn't be stopped the supple of gas or steam, the operation of band gas, and sample is shifted cooling section onto must strengthen throughput, anti-oxidation, every cover sample must add backplate, simultaneously tighten;
4, carry out surface observation and Data Detection after the annealing
The back observation steel plate specimen surface of coming out of the stove does not have warpage, distortion, dirtyization; Coating does not have and comes off; The non-oxidation phenomenon;
Detect the interface resistance and the tack of annealing back steel plate sample, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 139 Ω mm
2/ sheet;
Tack A level;
5, estimate the thermotolerance result
Qualified.
Embodiment six
1, sampling: the steel plate size of sample is 300 * 100mm;
2, detect the interface resistance and the tack of steel plate sample before the annealing, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 562 Ω mm
2/ sheet;
Tack O level;
3, the heat-resisting annealing process of steel plate sample
Unit type: hydrogen (nitrogen) protection electric furnace;
Annealing way: 100% nitrogen, atmosphere control mode: flowmeter control;
The annealing temperature time: 780 ± 5 ℃ * 2h;
The type of cooling: the water jacket natural cooling is cooled to 50 ℃ and stops the supple of gas or steam and come out of the stove;
200 ℃ begin ventilation, and 500 ℃ allow to shift onto cooling section, but forbid water flowing to be cooled off;
The experiment overall process definitely mustn't be stopped the supple of gas or steam, the operation of band gas, and sample is shifted cooling section onto must strengthen throughput, anti-oxidation, every cover sample must add backplate, simultaneously tighten;
4, carry out surface observation and Data Detection after the annealing
The back observation steel plate specimen surface of coming out of the stove does not have warpage, distortion, dirtyization; Coating does not have and comes off; The non-oxidation phenomenon;
Detect the interface resistance and the tack of annealing back steel plate sample, wherein:
Interface resistance (according to the IEC of International Electrotechnical Commission examination criteria) 188 Ω mm
2/ sheet;
Tack F level;
5, estimate the thermotolerance result
Defective.
Claims (5)
1. stable on heating evaluation method of cold rolled silicon steel insulating coating; Comprise that mainly sampling, heat-resisting annealing, annealing back observe specimen surface, it is characterized in that, before the annealing sample is carried out interface resistance and tack detection; The sample that satisfies condition is put into annealing furnace anneals; Specimen surface is observed in the annealing back, if open defect appears in the specimen surface of coming out of the stove, then is judged to be defective; If come out of the stove the specimen surface no significant defect, then sample is carried out the further detection of interface resistance and tack, and the thermotolerance of insulating coating is judged according to detecting data; The condition that sample satisfies before the said annealing is: interface resistance>=200 Ω mm
2/ sheet, and tack is more than the A level; The said specimen surface open defect of coming out of the stove is: specimen surface warpage, distortion, dirtyization, coating shedding, oxidation.
2. the stable on heating evaluation method of cold rolled silicon steel insulating coating according to claim 1 is characterized in that, if the interface resistance>=70 Ω mm of the sample of coming out of the stove
2/ sheet, and tack is more than the D level, and the thermotolerance of insulating coating is qualified, otherwise is defective.
3. the stable on heating evaluation method of cold rolled silicon steel insulating coating according to claim 1 is characterized in that heat-resisting annealing process is: in the mixed atmosphere of nitrogen, hydrogen or nitrogen and hydrogen, carry out; Annealing temperature is controlled at 750～820 ℃, and annealing time is controlled at 2～2.5h; Being cooled to 40～60 ℃ stops the supple of gas or steam and comes out of the stove.
4. the stable on heating evaluation method of cold rolled silicon steel insulating coating according to claim 3 is characterized in that, 100～200 ℃ begin ventilation, adopts water jacket natural cooling mode, and 400～500 ℃ allow to shift onto cooling section.
5. according to claim 1 or the stable on heating evaluation method of 3 described cold rolled silicon steel insulating coatings, it is characterized in that the sample of putting into annealing furnace is added with backplate, and with the sample tighten.
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| CN102527602B (en) * | 2012-01-30 | 2014-10-29 | 无锡华精新材股份有限公司 | Process for coating magnesium oxide on surface of oriented silicon steel strip |
| RU2505811C1 (en) * | 2012-06-14 | 2014-01-27 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "МАТИ-Российский государственный технологический университет имени К.Э. Циолковского" | Method for determining strength characteristics and value of grain in metallic materials and alloys |
Citations (4)
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|---|---|---|---|---|
| US4612805A (en) * | 1984-12-24 | 1986-09-23 | International Business Machines Corporation | Adhesion characterization test site |
| CN101168642A (en) * | 2007-10-25 | 2008-04-30 | 武汉钢铁(集团)公司 | Environment-friendly type insulated dope for cold rolling non-oriented silicon steel and preparation method for coat thereof |
| CN101314694A (en) * | 2008-06-29 | 2008-12-03 | 金坛市华荣绝缘材料厂 | Resin emulsion paint special for epoxy pnenolic aldehyde stalloy and preparation thereof |
| CN101358096A (en) * | 2008-09-05 | 2009-02-04 | 首钢总公司 | Insulation environment friendly paint for non-oriented electrical steel |
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2008
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4612805A (en) * | 1984-12-24 | 1986-09-23 | International Business Machines Corporation | Adhesion characterization test site |
| CN101168642A (en) * | 2007-10-25 | 2008-04-30 | 武汉钢铁(集团)公司 | Environment-friendly type insulated dope for cold rolling non-oriented silicon steel and preparation method for coat thereof |
| CN101314694A (en) * | 2008-06-29 | 2008-12-03 | 金坛市华荣绝缘材料厂 | Resin emulsion paint special for epoxy pnenolic aldehyde stalloy and preparation thereof |
| CN101358096A (en) * | 2008-09-05 | 2009-02-04 | 首钢总公司 | Insulation environment friendly paint for non-oriented electrical steel |
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