CN105316573B - 80-grade cord steel wire rod suitable for acid pickling and descaling and production method thereof - Google Patents
80-grade cord steel wire rod suitable for acid pickling and descaling and production method thereof Download PDFInfo
- Publication number
- CN105316573B CN105316573B CN201410282904.8A CN201410282904A CN105316573B CN 105316573 B CN105316573 B CN 105316573B CN 201410282904 A CN201410282904 A CN 201410282904A CN 105316573 B CN105316573 B CN 105316573B
- Authority
- CN
- China
- Prior art keywords
- wire rod
- less
- equal
- descaling
- percent
- 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.)
- Active
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 25
- 239000010959 steel Substances 0.000 title claims abstract description 25
- 238000005554 pickling Methods 0.000 title claims abstract description 13
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 239000002253 acid Substances 0.000 title abstract description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 54
- 229910052742 iron Inorganic materials 0.000 claims abstract description 27
- 238000000034 method Methods 0.000 claims abstract description 17
- 238000005096 rolling process Methods 0.000 claims abstract description 12
- 230000008569 process Effects 0.000 claims abstract description 10
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 7
- 238000007670 refining Methods 0.000 claims abstract description 7
- 239000000126 substance Substances 0.000 claims abstract description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 7
- 238000003723 Smelting Methods 0.000 claims abstract description 6
- 238000009749 continuous casting Methods 0.000 claims abstract description 6
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 6
- 230000008859 change Effects 0.000 claims abstract description 5
- 238000010438 heat treatment Methods 0.000 claims abstract description 5
- 238000009987 spinning Methods 0.000 claims abstract description 5
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052802 copper Inorganic materials 0.000 claims abstract description 4
- 238000002791 soaking Methods 0.000 claims abstract description 3
- 239000011593 sulfur Substances 0.000 claims abstract description 3
- 239000000203 mixture Substances 0.000 claims description 6
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 229910052748 manganese Inorganic materials 0.000 claims description 5
- 238000005266 casting Methods 0.000 claims description 4
- 230000003009 desulfurizing effect Effects 0.000 claims description 4
- 229910052749 magnesium Inorganic materials 0.000 claims description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 230000009466 transformation Effects 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 239000002893 slag Substances 0.000 claims description 2
- 238000001816 cooling Methods 0.000 abstract description 8
- 238000004140 cleaning Methods 0.000 abstract 1
- 239000011572 manganese Substances 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 5
- 239000011777 magnesium Substances 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229910000754 Wrought iron Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000005098 hot rolling Methods 0.000 description 4
- 230000009467 reduction Effects 0.000 description 3
- 229910000677 High-carbon steel Inorganic materials 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000004411 aluminium Substances 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 239000010813 municipal solid waste Substances 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229920001296 polysiloxane Polymers 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 206010008190 Cerebrovascular accident Diseases 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910001051 Magnalium Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 208000006011 Stroke Diseases 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
- Heat Treatment Of Steel (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
An 80-grade cord steel wire rod suitable for acid cleaning and descaling comprises the following chemical components in percentage by weight: 0.79-0.83% of C, 0.20-0.45% of Mn, 0.20-0.35% of Si, less than or equal to 0.010% of P, less than or equal to 0.010% of S, 0.0002-0.0010% of Mg0, Al: 0.00020 to 0005 percent and less than or equal to 0.05 percent of Cu. The sulfur content of the molten iron is less than 0.005 percent; converter smelting end point [ P]≤0.010％，[K]≤0.0001％，[Mg]Less than or equal to 0.0003 percent and less than or equal to 0.0002 percent of Al. LF refining temperature is 1530-1580 ℃, and time is 60-100 min. The superheat degree of molten steel of the continuous casting tundish is less than or equal to 30 ℃. The heating time of the continuous rolling blank is 2.5-3 h, and the lower soaking temperature is 1100 +/-15 ℃; the high-pressure water descaling pressure of the billet after being taken out of the heating furnace is not lower than 15 MPa; the wire rod spinning temperature is 860-890 ℃, and the final rolling deformation rate is less than or equal to 120s‑1The air cooling speed of the wire rod before phase change is 25-28 ℃/s, and the air cooling speed in the phase change process is 2-4 ℃/s. The thickness of the iron scale of the wire rod produced by the method is 4-8 um, and the performance requirements of users on pickling and descaling of the wire rod are met.
Description
Technical field
The invention belongs to metallurgical technology technical field, and in particular to a kind of 80 grades of cord steel disks suitable for later stage Pickling Descaling
Bar and its production method.
Background technology
Further violent with the competition in steel cord market, the requirement that user reduces its production cost is improved constantly.To steel curtain
For line user, in order to reduce its production cost, it is necessary to the thinner thickness of iron scale, and iron scale is based on FeO, makes
Iron sheet is easy to be dissolved by acid solution in Pickling Descaling process.
The patent of invention of Application No. 200810000916.1 describes a kind of control of hot rolling rod bundle surface iron scale
Technology, the throwing class high-carbon steel gren rod steel surface oxygen for adding Pickling Descaling using mechanical descaling method or mechanical descaling
Change the control of iron sheet.The thickness and knot of hot rolling rod bundle surface iron scale are controlled by controlling stelmor cooling technological process
Structure, specifically includes closing finish to gauge rear water box and regulation finish to gauge rear water box water to improve spinning temperature；High-temperature oxydation after increase spinning
Time, it will be moved behind phase change zone；Increase the fan delivery after Stanermo wind-cooling linear phase transformation to accelerate cooling velocity, improve FeO and exist
Shared proportion in hot rolling rod bundle surface iron scale.The present invention is effectively increased by controlling stelmor cooling technological process
The thickness of hot rolling rod bundle surface iron scale is added, has improved proportions of the FeO in iron scale, improve the knot of iron scale
Structure, is easy to mechanical descaling or the throwing class high-carbon steel gren rod steel surface iron scale of mechanical descaling acid adding washing method de-scaling
Processing.
But the patent and being not provided as improve wire rod iron sheet structure and the chemical composition that carries out and rolling mill practice it is detailed
Parameter.And its advantage is also only applicable to the throwing method of mechanical descaling or mechanical descaling acid adding washing method de-scaling.
The content of the invention
The purpose of the present invention, which aims to provide one kind, can effectively control iron scale thickness, and carry out Pickling Descaling suitable for the later stage
80 grades of Wire Rod Steel for Curtain String Purpose and its production method.
Therefore, this invention takes following technical solution：
A kind of 80 grades of Wire Rod Steel for Curtain String Purpose suitable for Pickling Descaling, its chemical composition wt% is：C：0.79%~0.83%,
Mn：0.20%~0.45%, Si：0.20%~0.35%, P≤0.010%, S≤0.010%, Mg：0.0002%~
0.0010%, Al：0.00020%~0005%, Cu≤0.05%, remaining is iron and residual elements.
The reasons why chemical composition and content are set is as follows：
Carbon is the main intensified element in steel, and carbon content is higher, and the tensile strength of wire rod and steel wire is bigger.But too high carbon
Content increases the stomata of wire rod iron scale, the oxidation rate increase of iron scale, causes thickness of scale larger.In order to produce
Suitable for 80 grades of Wire Rod Steel for Curtain String Purpose of Pickling Descaling, therefore by carbon content control in steel in 0.79%-0.83%.
Manganese, silicon are both a kind of element for improving wire rod intensity, are also the deoxidant element in steel.Relatively low manganese silicone content is unfavorable
In the tensile strength for improving wire rod, it is unfavorable for the control of the deoxidation degree of cord steel.But, too high manganese silicone content causes in steel
Manganese, silicon olivine are formed, makes the de-scaling penalty of steel billet, is unfavorable for the removal of an iron sheet, therefore is also just unfavorable for reduction
The iron scale thickness of final wire rod.Therefore by Mn controls in 0.20%~0.45%, Si controls 0.20%~0.35%.
Phosphorus, sulphur are all objectionable impurities elements in steel, it is desirable to wire rod P≤0.010%, S≤0.010%, are not causing other
It is more low better in the case of influence.
Magnesium, aluminium are all the morphotropism of field trash in strong deoxidant element, too high levels reduction wire rod；But too low oxygen content
It is unfavorable for expanding oxide in wire rod and is mingled with low melting point.Appropriate magnalium Ti content advantageously reduces what oxide in wire rod was mingled with
Fusing point, improves the morphotropism of field trash, therefore the content of magnesium of wire rod is controlled 0.0004~0.010%, and aluminium content control exists
0.0002~0.0005%.
Copper in wire rod can reduce the processing characteristics of wire rod, cause wire rod in the fracture of wire of drawing plying process, therefore control
Cu≤0.05%.
A kind of production method of 80 grades of Wire Rod Steel for Curtain String Purpose suitable for Pickling Descaling, its concrete technology method is：
1st, desulfurizing iron pretreatment, converter smelting and LF refining：
Desulfurizing iron pretreatment controls the sulfur content in molten iron below 0.005%；Converter carries out smelting using double slag process
Refining, smelting endpoint requires [P]≤0.010%, [K]≤0.0001%, [Mg]≤0.0003%, Al≤0.0002%.LF is concise
Process temperature is controlled at 1530~1580 DEG C, and 60~100min of time, the liquid steel refining time should not be too short, passes through certain time essence
Refining, may advantageously facilitate steel inclusion floating discharge molten steel, improves steel cleanliness factor；Meanwhile, LF stoves refining time also should not mistake
It is long, to prevent the excessive etch of tank lining material, deteriorate steel.
2nd, continuous casting：
The casting process control Metal in Tundish degree of superheat is not more than 30 DEG C, and square billet cross dimensions is (200~400) × (300
~500) mm.By bloom continuous casting and Prepared by Low Superheat Pouring, created conditions for control steel billet segregation.
3rd, tandem rolling and wire rod rolling：
Continuous casting billet is through continuous rolling into Concasting Bloom, and it is 2.5~3h that Concasting Bloom, which heats total time inside furnace, and lower soaking temperature exists
1100±15℃；Steel billet goes out the laggard horizontal high voltage water de-scaling of heating furnace, and de-scaling pressure is not less than 15MPa；Wire rod laying temperature 860~
890 DEG C, wire rod finish to gauge rate of deformation is controlled in≤120s-1, diameter 5.0~6.0mm wire rods are rolled out, prevent too high rolling from becoming
Shape speed causes after the rupture of wire rod scale on surface, and iron sheet is further aoxidized, thickness increase.In air-cooled roller-way after wire rod spinning
Upper to be cooled down, air-cooled 25~28 DEG C/s of speed before wire rod phase transformation, phase transition process apoplexy speed of cooling is controlled in 2~4 DEG C/s.
Beneficial effects of the present invention are：
The present invention is laid the foundation by controlling C, Si, Mn content for reduction wire rod iron scale thickness；By controlling steel billet
Heating-up temperature, high-pressure water descaling pressure, laying temperature and wire rod cooling velocity, make wire rod iron scale have suitable chemistry into
Divide and thickness.The wire rod produced using the inventive method, its iron scale thickness is carried out pickling in 4~8um, suitable for the later stage and removed
Squama, meets performance requirement of the user to wire rod Pickling Descaling.
Embodiment
With reference to embodiment, the invention will be further described.
Table 1 is embodiment chemical composition wt%.
The embodiment chemical composition wt% of table 1
| Embodiment | C, % | Si, % | Mn, % | P, % | S, % | Mg, % | Al, % | Cu, % |
| 1 | 0.79 | 0.22 | 0.22 | 0.0083 | 0.0037 | 0.0004 | 0.0002 | 0.01 |
| 2 | 0.81 | 0.32 | 0.37 | 0.0078 | 0.0031 | 0.0006 | 0.0004 | 0.02 |
| 3 | 0.83 | 0.35 | 0.45 | 0.0089 | 0.0075 | 0.0009 | 0.0005 | 0.04 |
Table 2 is that embodiment is smelted and casting parameters table.
The embodiment of table 2 is smelted and casting parameters table
Table 3 is embodiment rolling technological parameter table.
The embodiment rolling technological parameter table of table 3
Claims (1)
1. a kind of 80 grades of Wire Rod Steel for Curtain String Purpose production methods suitable for Pickling Descaling, it is characterised in that its chemical composition wt% is：C：
0.79%~0.83%, Mn：0.20%~0.37%, Si：0.20%~0.35%, P≤0.010%, S≤0.010%, Mg：
0.0002%~0.0010%, Al：0.00020%~0.0005%, Cu≤0.05%, remaining is iron and residual elements；Specifically
Process is：(1) desulfurizing iron pretreatment, converter smelting and LF refining：Desulfurizing iron is pre-processed the sulfur content in molten iron
Control is below 0.005%；Converter is smelted using double slag process, smelting endpoint requirement [P]≤0.010%, and [K]≤
0.0001%, [Mg]≤0.0003%, Al≤0.0002%；LF refinery practices temperature control is in 1530~1580 DEG C, time 60
~100min；(2) continuous casting：The casting process control Metal in Tundish degree of superheat is not more than 30 DEG C, square billet cross dimensions for (200~
400) × (300~500) mm；(3) tandem rolling and wire rod rolling：Continuous casting billet is through continuous rolling into Concasting Bloom, and Concasting Bloom heating always exists
The stove time is 2.5~3h, and lower soaking temperature is at 1100 ± 15 DEG C；Steel billet goes out the laggard horizontal high voltage water de-scaling of heating furnace, de-scaling pressure
It is not less than 15MPa；860~890 DEG C of wire rod laying temperature, wire rod finish to gauge rate of deformation is controlled in≤120s-1, roll out diameter
5.0~6.0mm wire rods；Cooled down after wire rod spinning on air-cooled roller-way, air-cooled 25~28 DEG C/s of speed, phase before wire rod phase transformation
Air-cooled speed control is in 2~4 DEG C/s during change.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410282904.8A CN105316573B (en) | 2014-06-23 | 2014-06-23 | 80-grade cord steel wire rod suitable for acid pickling and descaling and production method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410282904.8A CN105316573B (en) | 2014-06-23 | 2014-06-23 | 80-grade cord steel wire rod suitable for acid pickling and descaling and production method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105316573A CN105316573A (en) | 2016-02-10 |
| CN105316573B true CN105316573B (en) | 2017-07-21 |
Family
ID=55244886
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410282904.8A Active CN105316573B (en) | 2014-06-23 | 2014-06-23 | 80-grade cord steel wire rod suitable for acid pickling and descaling and production method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105316573B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107400823B (en) * | 2016-05-18 | 2019-02-26 | 鞍钢股份有限公司 | High-strength Ni-Cr corrosion-resistant steel strand wire rod and production method thereof |
| CN108998732A (en) * | 2018-08-08 | 2018-12-14 | 鞍钢股份有限公司 | Cord steel wire rod suitable for mechanical descaling and production method thereof |
| CN110029270A (en) * | 2019-04-02 | 2019-07-19 | 鞍钢股份有限公司 | Pickling-free dephosphorization high-carbon steel wire rod and production method thereof |
| CN110453153B (en) * | 2019-09-02 | 2021-04-02 | 鞍钢股份有限公司 | Low-cost cord steel wire rod and production method thereof |
| CN111647811A (en) * | 2020-05-29 | 2020-09-11 | 鞍钢股份有限公司 | Welding wire steel wire rod suitable for pickling-free shelling process and production method |
| CN111996349A (en) * | 2020-08-05 | 2020-11-27 | 鞍钢股份有限公司 | Production method of low-strength and high-elongation cord steel wire rod |
| CN113909295B (en) * | 2021-08-25 | 2024-04-02 | 江阴兴澄合金材料有限公司 | Production method of cord steel |
| CN114959504B (en) * | 2022-07-12 | 2023-10-20 | 鞍钢股份有限公司 | Acid-washing-free cord steel wire rod and production method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4980471B1 (en) * | 2011-01-07 | 2012-07-18 | 株式会社神戸製鋼所 | Steel wire rod and manufacturing method thereof |
| JP5299447B2 (en) * | 2011-02-23 | 2013-09-25 | 新日鐵住金株式会社 | Melting method of low Al steel |
| CN102952997B (en) * | 2011-08-19 | 2015-11-25 | 鞍钢股份有限公司 | Cord steel wire rod and Al thereof 2O3Inclusion control method |
| JP5879897B2 (en) * | 2011-10-07 | 2016-03-08 | 新日鐵住金株式会社 | Ultra fine steel wire with excellent delamination resistance and its manufacturing method |
-
2014
- 2014-06-23 CN CN201410282904.8A patent/CN105316573B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN105316573A (en) | 2016-02-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105316573B (en) | 80-grade cord steel wire rod suitable for acid pickling and descaling and production method thereof | |
| CN102703813B (en) | Vanadium and titanium compound microalloyed steel bar and production method thereof | |
| CN105543678B (en) | High intensity non-annealed steel for fastener wire rod of a kind of boracic and preparation method thereof | |
| CN102634730B (en) | Steel wire rod for 1860MPa-level bridge cable galvanized steel wire and manufacturing method thereof | |
| CN102703811B (en) | Titanium micro-alloyed 400MPa grade high-strength steel bar and production method thereof | |
| CN105316581B (en) | Wire rod for 90-grade ultrahigh-strength rubber tube steel wire and production method thereof | |
| CN102517522B (en) | Steel for hydraulic piece and manufacturing method for steel | |
| CN105925899B (en) | A kind of quenched and tempered state X52 hydrogen sulfide corrosion resistant seamless line pipes and preparation method thereof | |
| CN104233064B (en) | Cold rolling IF high-strength steel and the production method thereof of phosphorating of a kind of 170MPa level | |
| CN104438418A (en) | Rolling method of stainless steel mold cast steel ingot by one-heating forming | |
| CN101082106B (en) | Method for producing X65 pipe steel with low cost | |
| CN105483557A (en) | Wire rod for 80-grade cord outer winding and manufacturing method thereof | |
| CN101831521A (en) | Method for producing cord steel | |
| CN103194689A (en) | High-strength ferrite stainless steel with excellent formability and corrosion-resistant performance and preparation method thereof | |
| CN110951944A (en) | High-strength and high-hardness rare earth steel rail material subjected to online heat treatment and production method thereof | |
| CN103215410B (en) | A kind of method improved containing Nb, Ti steel cleanness | |
| CN105506479B (en) | Wire rod for 70-grade cord outer winding and production method thereof | |
| CN101892419B (en) | Method for producing low-carbon low-silicon high magnetic induction non-oriented electrical steel plate by CSP process | |
| CN107236902A (en) | A kind of half-hard state cable steel and production method | |
| CN104131238B (en) | High molding high durable Ultra-thin hot rolled steel plate and CSP production technology thereof | |
| CN106591703A (en) | Steel plate for pressure vessel with yield strength being 345 MPa stage and production method | |
| CN110195141B (en) | Preparation method of hot-rolled wire rod for grinding and polishing cotton steel | |
| WO2023071299A1 (en) | Steel for steel cord having tensile strength greater than or equal to 4,000 mpa and production method | |
| CN101792843B (en) | Production process of Nb-containing mill coil for automobile | |
| CN101921962A (en) | D-grade sucker rod steel and production method thereof |
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 |