CN105403480A - Determination method for center density of continuous casting slab - Google Patents
Determination method for center density of continuous casting slab Download PDFInfo
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- CN105403480A CN105403480A CN201510778910.7A CN201510778910A CN105403480A CN 105403480 A CN105403480 A CN 105403480A CN 201510778910 A CN201510778910 A CN 201510778910A CN 105403480 A CN105403480 A CN 105403480A
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- continuous casting
- sample
- casting billet
- density
- casting slab
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
Abstract
The invention belongs to the field of property detection for metal materials and specifically relates to a determination method for center density of a continuous casting slab. The determination method for the center density of the continuous casting slab provided by the invention comprises the following steps: a) taking samples A and B in same size respectively from a corner, 9-11mm away from the inferior part on the two sides, of a cross section of the continuous casting slab and from the center of the cross section; b) processing the surfaces of the samples A and B, cleaning and testing the density rho0 of the sample A and the mass mB of the sample B; c) performing wax-sealing on the sample B and testing the volume V of the sample B after being wax-sealed; d) substituting the acquired rho0, mB and v into the formula (I) and determining the central porosity of the continuous casting slab; and e) substituting the acquired theta into the formula (II), thereby determining the center density (D=1-theta) of the continuous casting slab. The method provided by the invention is free from interference caused by human factors; according to the method, the condition of the center density of the continuous casting slab can be quickly and accurately reflected; an accurate, effective and reasonable determination method for the center density of the continuous casting slab is supplied for the continuous casting technique.
Description
Technical field
The invention belongs to metal material Performance Detection field, be specifically related to a kind of assay method of continuous casting billet central dense degree.
Background technology
Over nearly 20 years, the progress of China's continuous casting production and continuous casting technology, has promoted the development of whole steel industry.Continuous casting technology, as one of the mark of steel and iron industry level, has become the major technique power of iron and steel production development.Along with the raising of productive capacity and the rich and varied of the market demand, slab quality ensures its importance aobvious all the more.Continuous casting billet quality inspection is one of key means of continuous casting quality of production guarantee.
The central dense degree (comprising center porosity and central pipe etc.) of continuous casting billet is the major defect affecting slab quality, and the center porosity of accurate description strand and central pipe defect are significant to the improvement of continuous casting process.In continuous casting is produced, often adopt sulphur print, hot acid wash and cold acid wash three kinds of low power detection methods to detect slab quality.And hot acid wash and cold acid wash can detect continuous casting billet center porosity and central pipe degree.
Hot acid wash the sample processed is placed in watery hydrochloric acid heat a period of time, due to watery hydrochloric acid to the segregation thing around the crackle of steel, be mingled with, crystal boundary and matrix have corrosion in various degree, therefore, the surface washed through hot acid shows crackle, segregation accumulation area, be mingled with and crystal boundary etc.Cold acid wash is substantially identical with hot acid wash effect, and does not need descaling bath and heating arrangement.These two kinds of method pickling degree are wayward, easily occur corrosion deficiency or excessive corrosion, and adopt manual observation and judgement to be subject to extraneous factor interference, and evaluation result is inaccurate.
Application number is " 201310226194.2 ", denomination of invention is " a kind of continuous casting billet center porosity or central pipe Quantitative Assessment Method ", disclose a kind of continuous casting billet center porosity or central pipe Quantitative Assessment Method, the method cuts the identical sample of size respectively at thickness of strand 1/4th and strand center, through processing the smooth finish making specimen surface reach certain, absolute ethyl alcohol is used to clean specimen surface.According to the measuring method of QB/T2855-2007 standard, measure the density of two samples of strand diverse location respectively.Thickness of strand 1/4th place sample density is ρ
0, continuous casting billet center sample density is ρ, with
value characterize the degree of center porosity or central pipe.This patent adopts drainage density measurement, and method is coarse, operates more loaded down with trivial details, and think that operation factors impact is comparatively large on the one hand, sample surfaces does not take plugging meter resultant error larger on the other hand; In addition this patent supposition thickness of strand 1/4th place selects sample density maximum and compares with center porosity district sample, and thickness of strand 1/4th mostly is column crystal and easily occurs crackle and segregation in reality, density in most cases not should be maximum position, and center porosity district is generally equiax crystal district and slab thickness 1/4th columnar zone is not more be most Perfected process.
Application number is " 201410792132.2 ", denomination of invention is " detection method of the subcutaneous quality of a kind of strand ", disclose the detection method of the subcutaneous quality of a kind of strand, the detection method of this kind of subcutaneous quality of strand, comprises the following steps: (1) cools: carry out water-cooled or slow cooling to strand; (2) burn off: after slab cooling, carries out burn off to the surface of strand, the iron scale of burn off casting billet surface and part surface; Wherein the degree of depth of burn off is 1 ~ 3mm; (3) clear up: the burn off position rinsing strand with water, and purge with oxygen; (4) observe: observe the subcutaneous mass defect of strand by the burn off position of strand.This detection method is applicable to online or off-line checks the subcutaneous quality of strand fast.This invention stresses the subcutaneous quality testing of strand, does not relate to the detection of strand interior solid degree.
Application number is " 201110004123.9 ", denomination of invention is " continuous casting billet solidified structure and defect dendrite corrode macroscopic examination reagent and preparation method ", disclose a kind of continuous casting billet solidified structure and defect dendrite corrosion macroscopic examination reagent and preparation method, reagent constituent is by mass percentage: cupric chloride 0.28 ~ 1.09%, magnesium chloride 0.17 ~ 0.27%, iron chloride 0.56 ~ 1.60%, mass concentration is the hydrochloric acid 1.28 ~ 1.30% of 36 ~ 38%, absolute ethyl alcohol 54.70 ~ 55.80%, surplus is water.Preparation method is: add water in a reservoir, then adds cupric chloride, magnesium chloride, iron chloride and hydrochloric acid; After added raw material dissolves completely, then add absolute ethyl alcohol, stir.This patent solves the problem that other corrosion reagents clearly cannot show continuous casting billet dendrite solidified structure, adopt the reagent of this patent to carry out continuous casting billet solidified structure and defect dendrite corrosion macroscopic examination, the continuous casting steel billet inherent vice of display has the advantages that do not expand, do not reduce former state display.This invention belongs to the traditional application of macroscopic examination on slab quality detects, and round of visits is long, and human factor impact is larger, does not have strict quantitative criterion to strand interior solid degree.
In summary, at present the detection of continuous casting billet central dense degree or voidage is gone back to the quantitative analysis method of neither one standard, majority of case is all that qualitative analysis obtains artificially, there is gross error, so, prior art basis lays down a criterion quantitative analysis method, can reflect the situation of strand central dense degree fast and accurately, is very necessary for continuous casting process provides accurate and effective theoretical foundation.
Summary of the invention
Technical matters to be solved by this invention is to provide one not by interference from human factor, can reflect the situation of strand central dense degree fast and accurately, provide the assay method of the continuous casting billet central dense degree of accurate and effective theoretical foundation for continuous casting process.
The assay method of a kind of continuous casting billet central dense of the present invention degree, comprises the following steps:
A, get continuous casting billet lateral cross section bight and get cuboid sample in subcutaneous 9 ~ 11mm place far from both sides, be denoted as A; Get the cuboid sample onesize with A in continuous casting billet lateral cross section center, be denoted as B;
B, Sample A and B surface to be processed, cleaning, the density p of test sample A
0with the quality m of sample B
b;
C, sample B to be sealed with wax, test seal with wax after the volume V of sample B;
D, the ρ measured in b, step c
0, m
bsubstitute in formula (I) with V and measure continuous casting billet central porisity rate θ:
E, the θ that Step d is measured substitute into the central dense degree D obtaining continuous casting billet in formula (II):
(Ⅱ)D＝1-θ。
The assay method of a kind of continuous casting billet central dense degree described above, wherein the size of Sample A and sample B is 45 ~ 55mm × 45 ~ 55mm × 45 ~ 55mm.
Further, as preferred technical scheme, the assay method of a kind of continuous casting billet central dense degree described above, the size of Sample A and sample B is preferably 50mm × 50mm × 50mm.
The assay method of a kind of continuous casting billet central dense degree described above, wherein Sample A and sample B surface adopt alcohol to clean.
The assay method of a kind of continuous casting billet central dense degree described above, wherein seals with wax to sample B, is at utmost reduce the error that causes of specimen surface cavity, and sample B is sealed with wax the thickness≤0.1mm of layer.
The assay method of a kind of continuous casting billet central dense of the present invention degree, density is higher to be on the one hand in fine grained region (equiax crystal) at continuous casting billet subcutaneous 10mm place sample thief, identical with the center porosity district crystal formation of coordination equiax crystal on the other hand, comparability is stronger; Puffs, center sample is sealed with wax and at utmost can reduce the empty error caused of specimen surface.The present invention's sampling can reflect the situation of strand central dense degree fast and accurately, is not affected by human factors, for continuous casting process provides accurate and effective theoretical foundation.
Embodiment
The assay method of a kind of continuous casting billet central dense of the present invention degree, comprises the following steps:
A, get continuous casting billet lateral cross section bight and get cuboid sample in subcutaneous 9 ~ 11mm place far from both sides, be denoted as A; Get the cuboid sample onesize with A in continuous casting billet lateral cross section center, be denoted as B;
B, Sample A and B surface to be processed, with alcohol washes, by the density p of real density analyser test sample A
0, with the quality m of precision balance test sample B
b;
C, sample B to be sealed with wax, the volume V of the sample B after sealing with wax with the test of real density analyser;
D, the ρ measured in b, step c
0, m
bsubstitute in formula (I) with V and measure continuous casting billet central porisity rate θ:
E, the θ that Step d is measured substitute into the central dense degree D obtaining continuous casting billet in formula (II):
(Ⅱ)D＝1-θ。
The assay method of a kind of continuous casting billet central dense degree described above, wherein the size of Sample A and sample B is 45 ~ 55mm × 45 ~ 55mm × 45 ~ 55mm.
Sample A of the present invention takes from the cube block at about 10mm place under continuous casting billet epidermis, is that density is higher because strand herein exists center porosity and central pipe hardly and is equiax crystal; And sample B takes from continuous casting billet lateral cross section center, be that center porosity district can be made so identical with the crystal formation being all equiax crystal, and comparability is high because the center porosity of continuous casting billet herein and central pipe are maximum.
Further, as preferred technical scheme, the assay method of a kind of continuous casting billet central dense degree described above, the size of Sample A and sample B is preferably 50mm × 50mm × 50mm.
Need to process specimen surface before the present invention's test, polish, clean, being the dirt in order to remove test samples surface, making specimen surface have certain smooth finish simultaneously, reduce impurity to the impact of experiment test.
Sample A and B surface are processed, after alcohol washes, by the density p of 3H-2000TD1 type real density analyser test sample A
0, because 3H-2000TD1 type real density analyser can the directly accurately density of test sample and volume, then use the quality m of high precision balance test sample B
b.
The assay method of a kind of continuous casting billet central dense degree described above, wherein sample B is sealed with wax, it is the error caused at utmost reduce specimen surface cavity, be specially the wax stove granular accurate paraffin being put into temperature control, set temperature is 100 DEG C of heating, because liquid paraffin is 100 DEG C time, meet normal temperature object and will reach the effect of speed leaching rapid-curing cutback, by clip, sample B is immersed speed to pick up, sample B surface coating will be very thin as sugar-coat one deck, in order to seal the hole of specimen surface, reduce wax layer to the impact of sample B volume simultaneously, sample B seal with wax layer thickness should≤0.1mm, then the volume of 3H-2000TD1 type real density analyser test sample B is used, because seal with wax, layer is very thin, almost can not have an impact to the volume of sample B, negligible.
The identical cuboid sample of size is got respectively with strand center at continuous casting billet subcutaneous about 10mm place, through processing, the smooth finish making specimen surface reach certain of cleaning and seal with wax, adopt 3H-2000TD1 type real density analyser to carry out density measurement to two samples, continuous casting billet subcutaneous 10mm place sample density is ρ
0, continuous casting billet center sample density is ρ, with
value characterize strand central dense degree.
Below in conjunction with embodiment, the specific embodiment of the present invention is further described, does not therefore limit the present invention among described scope of embodiments.
Embodiment 1U78CrV Properties of Heavy Rail Steel strand central dense degree measures.
Continuous casting production cross-sectional dimension is the U78CrV steel bloom of 320mm × 410mm, have employed the large press control of solidification end; In continuous casting billet lateral cross section bight, far from both sides, cuboid sample is got at subcutaneous 10mm place, is denoted as A; Get the cuboid sample onesize with A in continuous casting billet lateral cross section center, be denoted as B; A and B sample size is about 50mm × 50mm × 50mm.Sample A and B surface are processed, cleans with alcohol; By the density p of 3H-2000TD1 type real density analyser test sample A
0for 7.9487g/cm
3, be m by the quality of high precision balance test sample B
bfor 491.79g, seal with wax to sample B, after sealing with wax with the test of 3H-2000TD1 type real density analyser, the volume V of sample B is 62.3546cm
3.
Pass through formula
calculate porosity and be about 0.70%, the strand central dense degree value of porosity θ characterizes.
So central dense degree D=1-θ=99.30% of continuous casting billet.
Embodiment 2U78CrV steel strand central dense degree measures.
Continuous casting production cross-sectional dimension is the U78CrV steel bloom of 320mm × 410mm, have employed dynamic soft-reduction and controls; In continuous casting billet lateral cross section bight, far from both sides, cuboid sample is got at subcutaneous 10mm place, is denoted as A; Get the cuboid sample onesize with A in continuous casting billet lateral cross section center, be denoted as B; A and B sample size is about 50mm × 50mm × 50mm.Sample A and B surface are processed, cleans with alcohol; By the density p of 3H-2000TD1 type real density analyser test sample A
0for 7.9360g/cm
3, be m by the quality of high precision balance test sample B
bfor 486.83g, seal with wax to sample B, after sealing with wax with the test of 3H-2000TD1 type real density analyser, the volume V of sample B is 61.9016cm
3.
The strand central dense degree value of porosity θ characterizes.Pass through
calculate porosity and be about 0.90%.
So central dense degree D=1-θ=99.10% of continuous casting billet.
Embodiment 345# steel strand central dense degree measures.
Continuous casting production cross-sectional dimension is the 45# steel bloom of 360mm × 450mm, have employed the large press control of solidification end; In continuous casting billet lateral cross section bight, far from both sides, cuboid sample is got at subcutaneous 10mm place, is denoted as A; Get the cuboid sample onesize with A in continuous casting billet lateral cross section center, be denoted as B; A and B sample size is about 50mm × 50mm × 50mm.Sample A and B surface are processed, cleans with alcohol; By the density p of 3H-2000TD1 type real density analyser test sample A
0for 7.9453g/cm
3, be m by the quality of high precision balance test sample B
bfor 496.77g, seal with wax to sample B, after sealing with wax with the test of 3H-2000TD1 type real density analyser, the volume V of sample B is 62.9138cm
3.
The strand central dense degree value of porosity θ characterizes.Pass through
calculate porosity and be about 0.62%.
So central dense degree D=1-θ=99.38% of continuous casting billet.
Claims (5)
1. an assay method for continuous casting billet central dense degree, is characterized in that: comprise the following steps:
A, get continuous casting billet lateral cross section bight and get cuboid sample in subcutaneous 9 ~ 11mm place far from both sides, be denoted as A; Get the cuboid sample onesize with A in continuous casting billet lateral cross section center, be denoted as B;
B, Sample A and B surface to be processed, cleaning, the density p of test sample A
0with the quality m of sample B
b;
C, sample B to be sealed with wax, test seal with wax after the volume V of sample B;
D, the ρ measured in b, step c
0, m
bsubstitute in formula (I) with V and measure continuous casting billet central porisity rate θ:
(Ⅰ)
E, the θ that Step d is measured substitute into the central dense degree D obtaining continuous casting billet in formula (II):
(Ⅱ)D＝1-θ。
2. the assay method of a kind of continuous casting billet central dense degree according to claim 1, is characterized in that: the size of Sample A and sample B is 45 ~ 55mm × 45 ~ 55mm × 45 ~ 55mm.
3. the assay method of a kind of continuous casting billet central dense degree according to claim 2, is characterized in that: the size of Sample A and sample B is 50mm × 50mm × 50mm.
4. the assay method of a kind of continuous casting billet central dense degree according to claim 1, is characterized in that: Sample A and sample B surface adopt alcohol to clean.
5. the assay method of a kind of continuous casting billet central dense degree according to claim 1, is characterized in that: sample B is sealed with wax the thickness≤0.1mm of layer.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113129259A (en) * | 2021-03-03 | 2021-07-16 | 中冶南方连铸技术工程有限责任公司 | Casting blank density detection method and system and electronic equipment |
| CN116699097A (en) * | 2023-07-28 | 2023-09-05 | 北京科技大学 | Nondestructive testing method for solidification structure of high-strength steel for automobile |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3543567A (en) * | 1967-11-20 | 1970-12-01 | Concast Ag | Method of intensifying reflection of ultrasonic waves from boundary between solid and liquid metal |
| CN102721627A (en) * | 2011-03-29 | 2012-10-10 | 厦门钨业股份有限公司 | Method for detecting density of porous material |
| CN103278424A (en) * | 2013-06-07 | 2013-09-04 | 南京钢铁股份有限公司 | Quantitative evaluation method for continuous casting billet center porosity or center shrinkage cavity |
| CN104535388A (en) * | 2014-12-19 | 2015-04-22 | 山东钢铁股份有限公司 | Method for detecting casting blank skin quality |
-
2015
- 2015-11-12 CN CN201510778910.7A patent/CN105403480B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3543567A (en) * | 1967-11-20 | 1970-12-01 | Concast Ag | Method of intensifying reflection of ultrasonic waves from boundary between solid and liquid metal |
| CN102721627A (en) * | 2011-03-29 | 2012-10-10 | 厦门钨业股份有限公司 | Method for detecting density of porous material |
| CN103278424A (en) * | 2013-06-07 | 2013-09-04 | 南京钢铁股份有限公司 | Quantitative evaluation method for continuous casting billet center porosity or center shrinkage cavity |
| CN104535388A (en) * | 2014-12-19 | 2015-04-22 | 山东钢铁股份有限公司 | Method for detecting casting blank skin quality |
Non-Patent Citations (1)
| Title |
|---|
| 葛若东: "《土建专业岗位基础知识》", 30 April 2015 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113129259A (en) * | 2021-03-03 | 2021-07-16 | 中冶南方连铸技术工程有限责任公司 | Casting blank density detection method and system and electronic equipment |
| CN116699097A (en) * | 2023-07-28 | 2023-09-05 | 北京科技大学 | Nondestructive testing method for solidification structure of high-strength steel for automobile |
| CN116699097B (en) * | 2023-07-28 | 2023-10-10 | 北京科技大学 | Nondestructive testing method for solidification structure of high-strength steel for automobile |
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