CN1084798C - Method for producing high toughness, high wear resistant steel of slurry pipeline - Google Patents
Method for producing high toughness, high wear resistant steel of slurry pipeline Download PDFInfo
- Publication number
- CN1084798C CN1084798C CN99107807A CN99107807A CN1084798C CN 1084798 C CN1084798 C CN 1084798C CN 99107807 A CN99107807 A CN 99107807A CN 99107807 A CN99107807 A CN 99107807A CN 1084798 C CN1084798 C CN 1084798C
- Authority
- CN
- China
- Prior art keywords
- steel
- toughness
- slurry pipeline
- content
- wear resistant
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
The present invention relates to a method for producing high toughness and high wear resistance steel for a slurry pipeline. The steel is coiled after smelted, forged, hot rolled and cooled. The chemical composition (weight %) of the steel comprises: 0.02 to 0.05 of C, 0.50 to 1.0 of Mn, 0.15 to 0.45 of Si, 0.50 to 0.80 of Cr, 0.15 to 0.40 of Cu, 0.10 to 0.25 of Ni, 0.15 to 0.30 of Mo, 0.02 to 0.05 of Nb, 0.0010 to 0.0080 of Ca, 0.0070 to 0.03 of N, 0.01 to 0.022 of Ti, and at most 0.0060 of S. Coiling temperature is 520 DEG C to 560 DEG C. The present invention has the advantages that the functions of solid solution nitrogen and precipitated nitride are fully used, and good strength and toughness match and welding property and high wear resistance are obtained.
Description
The present invention relates to a kind of manufacture method of steel alloy, particularly a kind of slurry line of pipes manufacture method of steel.
At present, research-and-development activity at slurry (coal slurry, mortar and ore pulp etc.) line of pipes steel still is in the starting stage, at present all be to substitute with serial pipe line steel of the X-of transfer oil and Sweet natural gas or weathering steel, X-60 for example, its composition is: C 0.08～0.12, Mn1.2～1.5, Nb＜0.05, V＜0.05, Ti＜0.05.Some steel grade also adds Cu, Ni, Mo.Since the slurry pipeline carry steel require high tenacity, high welding performance, high strength (＞420MPa), this steel is in liquid-solid two-phase media work simultaneously, be subjected to the dual function of the abradability of the corrodibility of liquid medium and solid particulate, the resistance to abrasion of existing pipe line steel is difficult to satisfy technical requirements.For example the U.S. used the X-52 pipe line steel to carry phosphorus ore in 1984～1991 years, found that through using tube wall abrasion rate is 230 μ m/, surpassed standard 150 μ m/, changed X-56 in some location afterwards, but its tube wall abrasion rate still surpasses standard.Its reason is: the method that improves resistance to abrasion can reduce the weldability of steel.Vice versa.Therefore, existing alloying process can't just be to be difficult to solve the contradiction of weldability and resistance to abrasion in the basic reason that makes a breakthrough aspect the slurry line of pipes steel.For solving this contradiction, that the clear 53-46445 of Japanese Patent Application Laid-Open discloses is a kind of " manufacture method with steel plate of low-temperature flexibility, anti-corrosion, excellent in wear resistance ", be to adopt clad steel plate to make this steel pipe, its surface is for containing the steel alloy layer of Cr, Ni, Cu, has good resistance to abrasion, and nexine is general micro-alloyed steel, guarantees good toughness and weldability.Its manufacture method complexity, cost height.
The objective of the invention is to obtain a kind of manufacture method of steel of slurry pipeline, by with alloying constituent and cooling controlling and rolling controlling process combination, can make this steel obtain high tenacity, good weldability and the good combination of high wear resistant.
For achieving the above object, the technical solution of the present invention's proposition is:
The manufacture method of a kind of high tenacity, high wear resistant steel of slurry pipeline, be through batching after smelting, forging, hot rolling, the cooling, the chemical ingredients of this steel (weight %) is: C0.02～0.05, Mn 0.50～1.0, Si 0.15～0.45, Cr 0.50～0.80, Cu0.15～0.40, Ni 0.10～0.25, Mo 0.15～0.30, Nb 0.02～0.05, Ca0.0010～0.0080, N 0.0070～0.03, Ti 0.01～0.022, S≤0.0060, coiling temperature is: 540 ± 20 ℃.
The chemical ingredients of this steel (weight %) is: C 0.03～0.05, Mn 0.60～0.8, Si 0.18～0.40, Cr 0.65～0.75, Cu 0.20～0.30, Ni 0.10～0.20, Mo0.15～0.25, Nb 0.03～0.05, Ca 0.0020～0.0050, N 0.0080～0.02, Ti 0.010～0.020,1 * 10
-5≤ [Ti] [N]≤3.5 * 10
-5
Fig. 1 is Ti, N concentration relationship in the steel of the present invention.
Fig. 2 tests the influence of hardness of steel to the present invention for nitrogen content.
The below does the present invention and is described in further detail.
Key problem in technology of the present invention is: adopt the nitrogen alloying technology, carbon drop nitrogen pick-up takes full advantage of it to the advantageous effect of the resistance to abrasion of steel, reduces simultaneously the carbon in the steel, to improve welding performance. In addition, this composition is combined with cooling controlling and rolling controlling process, to form acicular ferrite, the high tenacity of assurance design steel, good weldability and the good combination of high wear resistant obtain intensity and are equivalent to the nitrogenous slurry delivery pipe line steel of X60 level.
Since the useful effect that nitrogen improves the corrosion resistance of steel was familiar with, nitrogen was at stainless steel, even obtained in other steel to use more and more widely, and this has changed on traditional metallurgy the view of nitrogen as harmful element. In fact, except improving corrosion resistance, nitrogen is also because its strong work hardening effect, and is conducive to the shock-resistant abrasiveness of steel. Because solid solution nitrogen has the strong effect of pinning dislocation, undeniable, it is to the harmful effect of toughness. But should consider, suitably titanium combination in nitrogen and the steel, can the equal thermal process of refinement in austenite crystal, thereby favourable to the toughness of toughness, particularly welding heat affected zone. Because nitrogen and carbon when adding nitrogen, can reduce carbon content in the steel, thereby reduce carbon equivalent aspect stable and the formation austenite similar effect being arranged, and further improve weldability.
The below is introduced the effect of each alloying element among the present invention:
C:0.02～0.05 (weight %, as follows), the principal element of solution strengthening, but its content will reduce toughness and welding property as too high, its content control 0.02～0.05.Make carbon equivalent reduce C
Eq＜0.380, and cold crack indices P cm＜0.160, to guarantee good weldability.
Mn:0.50～1.0, the important element of solution strengthening, and also the Mn of certain content helps the acquisition of bainite.But its content must be controlled, otherwise improves carbon equivalent, influences welding property.
There is certain desoxydatoin Si:0.15～0.45 in steel, simultaneously limited amount Si and Ca is compound can be with Al
2O
3Sex change is CaO.Al
2O
3.SiO
2, help the formation of acicular ferrite, favourable to the obdurability that improves steel.
The solution strengthening effect is played on the one hand in Cr:0.50～0.80, can improve the corrosion resistance nature of steel on the other hand, when too high as content, will improve carbon equivalent, reduces welding property,
The solution strengthening effect is played on the one hand in Cu:0.15～0.40, can improve the corrosion resistance nature of steel on the other hand.But too high as its content, will improve carbon equivalent, influence welding property.And can reduce hot workability.
Ni:0.10-0.25 plays the solution strengthening effect on the one hand, can improve the corrosion resistance nature of steel on the other hand, and approximately the Ni of 50%Cu content can reduce even eliminate hot-short that C causes simultaneously.But too high as its content, will improve carbon equivalent, reduce welding property.
Mo:0.15～0.30, most important effect is the phase-change characteristic that influences steel, the formation of acicular ferrite when helping low temperature to curl.In addition, it can improve corrosion resistance nature.When too high as its content, will improve carbon equivalent, reduce welding property.
Nb:0.02～0.05, microalloy element can improve recrystallization temperature in the controlled rolling process, and separating out of its carbonitride can thinning microstructure, thereby improves the intensity and the toughness of steel.Generally speaking 0.02～0.05 Nb is enough.
Ca:0.0010～0.0080 to the sulfide sex change, is controlled its form, thereby is improved transverse toughness.But because its vapour pressure is too high, be not easy to add molten steel, for this reason its content control 0.0010～0.0080.
S≤0.0060, impurity element is low more good more.
N:0.0070～0.03, (solid solution nitrogen can improve erosion resistance, and the work-hardening effect of its generation can improve the resistance to abrasion of steel, and the Ti (C, existence N) also helps the resistance to abrasion of steel) that part exists can to improve the resistance to abrasion of steel in steel.Simultaneously, because the work hardening effect of nitrogen, the intensity that the cold hardening effect when making pipe by coiled sheet causes improves the reduction that can offset the intensity that the Bao Geshen effect causes.In addition, (C, having N) is beneficial to the formation acicular ferrite to Ti, further improves the obdurability of steel.But the nitrogen that content is too high will reduce the toughness of steel.
Ti:0.01～0.022, with the N combination, forming TiN can particle, hinder austenite crystal and grow up, thereby the obdurability of steel improves in refinement phase-change organization.But its content must be controlled at 1 * 10
-5≤ [Ti] [N]≤3.5 * 10
-4, TiN separates out from austenite with assurance, rather than separates out from molten steel.
Key of the present invention is to adopt the N alloying process, utilizes N to replace portion C (reducing C content), improves the obdurability of steel, formation Ti (C N) helps forming acicular ferrite, and by controlling the influence to ferrite grain size and pattern of N and Ti content.
What in fact the influence of N and Ti content reflected is the influence of TiN precipitated phase in the steel.It is generally acknowledged that the TiN in the steel has the effect that austenite crystal is grown up when hindering soaking, thereby make the ferrite crystal grain refinement after the phase transformation.Simultaneously, it still is effective core of acicular ferrite nucleating.But, the TiN in the steel separates out from austenite, rather than when separating out from liquid phase, above-mentioned effect is arranged.This just requires, and [Ti] [N] concentration is long-pending during less than 1500 ℃ and the threshold value of liquid equilibrium in the steel, but during greater than 1300 ℃ and austenite equilibrated threshold value.They are calculated by following two equations respectively.
TiN and austenite balance: lg[Ti] [N]=0.32-8000/T (1)
TiN and liquid equilibrium: lg[Ti] [N]=5.9-16586/T (2)
T is a temperature, and equation (1) is got 1573K, and equation (2) is got 1773K, through above-mentioned equation (1), (2) of deriving, obtains 1 * 10
-5≤ [Ti] [N]≤3.5 * 10
-4
Coiling temperature is: 540 ± 20 ℃, owing to add Mo the transition point of bainite is reduced, and therefore need batch at low temperature; Guarantee to form acicular ferrite simultaneously.
Introduce effect of the present invention below in conjunction with embodiment and accompanying drawing.
Present embodiment is smelted in the 50kg non-vacuum induction furnace of laboratory, utilizes the method for nitrogen and N-Mn-Fe alloy adding, steel is carried out the alloying of nitrogen.The chemical ingredients of the four stove steel of being smelted is as shown in table 1.Other alloying constituent basically identical of four stove steel, have only N and Ti content have a mind to from 0.0070% to 0.030% respectively,＜0.01% to 0.022% change.
Steel ingot forges into the thick slab of 42mm, with the thickness of simulation continuously cast bloom, forges the back air cooling.This slab is simulated hot rolling, acceleration cooling (water drenches cooling) and curling on little milling train, be processed into the plate that thickness is 7mm.The soaking temperature of steel is that 1250 ℃, finishing temperature are that 850 ℃, the temperature of curling are respectively 540 and 600 ℃.
Longitudinally intercept the tabular tension specimen that meets the API standard on the 7mm plate after rolling and carry out tension test, measure yield strength σ
0.5, tensile strength sigma
bWith unit elongation δ
50Shock test to the ISO-V type impact specimen of intercepting 5 * 10 * 10mm, is carried out in length and breadth in the edge under-20 ℃ simultaneously, measures its impelling strength, and its value is converted into standard test specimen 10 * 10 * 10mm impact value.In addition, the tissue of plate after forging and hot rolling metallographic and scanning electron microscopic observation have been carried out.
The present invention has analyzed N and Ti content, coiling temperature to ferrite grain size size, pattern with to the influence of acicular ferrite nucleating.
1.N and Ti content is to the influence of ferrite grain size
Metallographicobservation shows: the original structure of four stove steel before hot rolling is granular ferrite+a small amount of perlite, along with ferrite grain size in the different steel of composition is different with perlite area umber.From perlite area umber, in No. 2 steel minimum, about 4%, 1 and No. 3 steel more, be about 5%, and No. 4 steel are maximum, are 6%.
2.[Ti] [N] to the influence of ferrite grain size and pattern
Referring to Fig. 1, on [Ti], [N] concentration relationship figure, provided the straight line of desirable stoicheiometry Ti/N=3.42, provided simultaneously TiN respectively with austenite balance (1300 ℃) and with the curve of liquid equilibrium (1500 ℃), corresponding four stoves test steel also shows in the drawings.As can be seen, they all are lower than the liquid equilibrium line, but are higher than the austenite line of balance, and this shows that all tests TiN particles in steel separate out from austenite, they have refinement ferrite size and promote the effect of acicular ferrite nucleating, and the intensity of steel is had certain vital role.[N] [Ti] concentration is long-pending the highest in No. 2 steel, below reduces by No. 1, No. 3 and No. 4 orders.Experimental result shows, it hinders, and austenite crystal is grown up and the tendency that forms acicular ferrite is also successively decreased successively.This proves absolutely TiN particulate importance.
3. coiling temperature is to the influence of ferrite crystal grain pattern
Compare the tissue obvious refinement of test steel after the metallographic structure when batching for 540 and 600 ℃ shows hot rolling after the hot rolling with the original structure before the hot rolling; 540 ℃ of curling acicular ferrite+granular ferrites that are organized as.600 ℃ curling organizes then based on granular ferrite, and other has a small amount of acicular ferrite.
The test steel is as shown in table 2 through intensity and plasticity after the hot rolling.As can be seen, all test steel 540 ℃ when curling intensity and the plasticity level considerably beyond the technological standard of X60 pipe line steel, its yield tensile ratio σ
0.5/ σ
bIn 0.84～0.88 scope.Highly significant be that the intensity of four stove steel increases progressively by the order of 1,2,3 and No. 4 steel basically, and plasticity reduces, but changes less relatively.Nitrogen in steel content to the influence of intensity as shown in Figure 2.
The present invention makes full use of solid solution nitrogen and the advantageous effect of separating out nitride owing to suitably utilize the alloying of nitrogen in the scope of [N]=0.0080～0.02, obtained good combination of strength and toughness: yield strength σ
0.5=487～520MPa, tensile strength sigma
b=561～591MPa, yield tensile ratio 0.84～0.88, plasticity δ
50=29～33% ,-20 ° of impact of collision toughness CVN=180～200J/cm
2, and transverse impact toughness CVN=150～190J/cm
2Mandatory declaration be, these results laboratory steel-making (S content up to 70～80ppm) and little milling train hot rolling test (cooling power is lower than industrial production scene) condition under obtain.Have reason to believe that industrial level in kind will be better.
The chemical ingredients of table 1 test steel, wt%
| Grade of steel | C | Si | Mn | Cr | Ni | Cu | Mo | Nb | N | Ti | P | S | Ca |
| 1 | 0.04 | 0.26 | 0.65 | 0.74 | 0.16 | 0.22 | 0.20 | 0.036 | 0.0070 | 0.020 | 0.018 | 0.0080 | 0.0046 |
| 2 | 0.05 | 0.30 | 0.72 | 0.67 | 0.15 | 0.21 | 0.20 | 0.033 | 0.0130 | 0.022 | 0.021 | 0.0070 | 0.0036 |
| 3 | 0.03 | 0.18 | 0.78 | 0.71 | 0.14 | 0.22 | 0.23 | 0.034 | 0.0190 | 0.011 | 0.019 | 0.0080 | 0.0046 |
| 4 | 0.03 | 0.41 | 0.68 | 0.66 | 0.17 | 0.21 | 0.20 | 0.033 | 0.0300 | ＜0.01 | 0.019 | 0.0070 | 0.0007 |
The mechanical property of steel after the different coiling temperature hot rollings of table 2
| Coiling temperature ℃ | Grade of steel | Yield strength σ 0.5，MPa | Tensile strength sigma b，MPa | σ 0.5/ σ b | Unit elongation δ 50，％ | -20 ℃ of impact of collision toughness J/cm 2 | -20 ℃ of transverse impact toughness J/cm 2 |
| 540 | 1 | 494 | 561 | 0.88 | 33 | 180 | 175 |
| 2 | 487 | 580 | 0.84 | 31 | 200 | 190 | |
| 3 | 520 | 591 | 0.86 | 30 | 195 | 150 | |
| 4 | 532 | 602 | 0.88 | 30 | 160 | 90 | |
| 600 | 1 | 418 | 487 | 0.86 | 43.5 | ||
| 2 | 434 | 509 | 0.85 | 39.5 | |||
| 3 | 451 | 513 | 0.88 | 40 | |||
| 4 | 465 | 537 | 0.87 | 35.5 |
Claims (2)
1. the manufacture method of a high tenacity, high wear resistant steel of slurry pipeline, be through batching after smelting, forging, hot rolling, the cooling, it is characterized in that: the chemical ingredients of this steel (weight %) is: C 0.02～0.05, Mn 0.50～1.0, Si 0.15～0.45, Cr0.50～0.80, Cu 0.15～0.40, Ni 0.10～0.25, Mo 0.15～0.30, Nb0.02～0.05, Ca 0.0010～0.0080, N 0.0070～0.03, Ti 0.01～0.022, S≤0.0060, coiling temperature is: 540 ± 20 ℃.
2. the manufacture method of high tenacity according to claim 1, high wear resistant steel of slurry pipeline is characterized in that: the chemical ingredients of this steel (weight %) is: C 0.03～0.05, Mn 0.60～0.8, Si 0.18～0.40, Cr 0.65～0.75, Cu 0.20～0.30, Ni 0.10～0.20, Mo 0.15～0.25, Nb 0.03～0.05, Ca 0.0020～0.0050, N 0.0080～0.02, Ti 0.010～0.020,1 * 10
-5≤ [Ti] [N]≤3.5 * 10
-4, S≤0.0060.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99107807A CN1084798C (en) | 1999-05-31 | 1999-05-31 | Method for producing high toughness, high wear resistant steel of slurry pipeline |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99107807A CN1084798C (en) | 1999-05-31 | 1999-05-31 | Method for producing high toughness, high wear resistant steel of slurry pipeline |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1236020A CN1236020A (en) | 1999-11-24 |
| CN1084798C true CN1084798C (en) | 2002-05-15 |
Family
ID=5272951
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN99107807A Expired - Fee Related CN1084798C (en) | 1999-05-31 | 1999-05-31 | Method for producing high toughness, high wear resistant steel of slurry pipeline |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1084798C (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100366780C (en) * | 2004-09-10 | 2008-02-06 | 宝山钢铁股份有限公司 | Needle ferrichrome-X70 pipeline steel with high crack-arresting toughenss and its production |
| CN100434561C (en) * | 2005-07-26 | 2008-11-19 | 武汉钢铁(集团)公司 | Steel in use for soldering pressure pipe in hydraulic power station under large line energy, and manufacturing method |
| CN100420769C (en) * | 2006-08-24 | 2008-09-24 | 武汉钢铁(集团)公司 | Rolling controlled and cooling controlled steel for hydraulic power station penstock and manufacture method thereof |
| CN100580123C (en) * | 2008-08-29 | 2010-01-13 | 攀钢集团研究院有限公司 | High strength anti-weathering steel and producing method thereof |
| CN102041458A (en) * | 2009-10-23 | 2011-05-04 | 宝山钢铁股份有限公司 | Low-alloy abrasion-resistant steel and manufacturing method thereof |
| CN102776445B (en) * | 2012-07-27 | 2014-01-29 | 攀枝花贝氏体耐磨管道有限公司 | Lower bainite wear-resisting steel tube for slurry transport and production method of steel tube |
| CN102747292B (en) * | 2012-07-31 | 2015-04-22 | 首钢总公司 | Normalized acid-resistant pipeline steel X52NS hot rolled plate coil and producing method thereof |
| CN106435398B (en) * | 2016-10-15 | 2017-12-29 | 睿智钢业有限公司 | Corrosion-resistant welded structural steel and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10237583A (en) * | 1997-02-27 | 1998-09-08 | Sumitomo Metal Ind Ltd | High tensile strength steel and its production |
-
1999
- 1999-05-31 CN CN99107807A patent/CN1084798C/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10237583A (en) * | 1997-02-27 | 1998-09-08 | Sumitomo Metal Ind Ltd | High tensile strength steel and its production |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1236020A (en) | 1999-11-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105937010B (en) | A kind of modified 09GrCuSb steel for resisting sulfuric acid dew point corrosion and its manufacturing method | |
| CN105803308B (en) | A kind of the 45MnVS easy-cutting untempered steels and its manufacturing method of the calcium containing magnesium | |
| CN109082594B (en) | Acid soil corrosion resistant steel for buried structure and manufacturing method thereof | |
| CN111057945B (en) | 500 MPa-level high-toughness weather-resistant bridge steel and preparation method thereof | |
| CN110295320A (en) | A kind of big wall thickness X52MS acid-resistant pipeline steel plate and its manufacturing method of the production of LF-RH refinery practice | |
| CN106939391A (en) | A kind of Ca microalloyings easy-cutting high strength fractured connecting rod steel and manufacture method | |
| CN109082595B (en) | Steel for alkali-resistant soil corrosion buried structure and manufacturing method thereof | |
| CN110438402B (en) | 1000 Mpa-grade sulfuric acid dew point corrosion resistant bolt steel and preparation method thereof | |
| CN1318631C (en) | Method for producing high strength high toughness X80 pipeline steel and its hot-rolled plate | |
| CN114182180A (en) | Steel plate containing Sn and Sb and resisting to corrosion of sulfuric acid and chloride ions and manufacturing method thereof | |
| JP3732424B2 (en) | Manufacturing method of hot-rolled steel sheet with high weather resistance and high workability | |
| CN102325909A (en) | Method of manufacturing sheet steel for sour-resistant line pipe | |
| CN108004488B (en) | Marine climate-resistant high-toughness bridge steel plate and production method thereof | |
| CN107974622B (en) | A kind of straight-line joint submerged arc welding tube X80 Pipeline Steel Plate and the production method of thickness >=26.4mm | |
| CN105624562A (en) | Steel for ultra-high-strength sucker rod and production method thereof | |
| CN113789480A (en) | Cold-forged gear steel and preparation method thereof | |
| CN1084798C (en) | Method for producing high toughness, high wear resistant steel of slurry pipeline | |
| CN114318140A (en) | Pipeline steel with excellent acid resistance and manufacturing method thereof | |
| CN111074155B (en) | High-strength hydrogen sulfide corrosion-resistant oil well pipe steel and preparation method thereof | |
| CN1594633A (en) | Dampproof hydrogen sulfide stress corrosion steel and preparing method thereof | |
| CN107236906B (en) | Corrosion-resistant conduit and its production method | |
| US8747575B2 (en) | 655 MPa grade martensitic stainless steel having high toughness and method for manufacturing the same | |
| CN1143688A (en) | Al-Mn-Si-N series austenitic stainless acid-resisting steel | |
| CN111411305B (en) | High-toughness high-Ti low-alloy steel with thick glass lining and good glass lining performance and manufacturing method thereof | |
| CN114182170A (en) | X80-grade hot-bending elbow with excellent welding performance and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| ASS | Succession or assignment of patent right |
Owner name: BAOSHAN IRON & STEEL CO., LTD. Free format text: FORMER OWNER: BAOSHAN STEEL GROUP IRON AND STEEL CO LTD Effective date: 20010928 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20010928 Address after: Orchard, Fujin Road, Baoshan District, Shanghai Applicant after: Baoshan Iron & Steel Co., Ltd. Address before: No. 1, middle section, factory road, Shanghai, Baoshan District Applicant before: Baoshan Iron & Steel (Group) Co., Ltd. |
|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20020515 Termination date: 20130531 |