CN103484754A - Production method of spheroidal graphite cast iron for planet carrier - Google Patents
Production method of spheroidal graphite cast iron for planet carrier Download PDFInfo
- Publication number
- CN103484754A CN103484754A CN201310377244.7A CN201310377244A CN103484754A CN 103484754 A CN103484754 A CN 103484754A CN 201310377244 A CN201310377244 A CN 201310377244A CN 103484754 A CN103484754 A CN 103484754A
- Authority
- CN
- China
- Prior art keywords
- iron
- planet carrier
- spheroidal graphite
- cast iron
- graphite cast
- 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.)
- Granted
Links
Landscapes
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Abstract
The invention provides a production method of spheroidal graphite cast iron for a planet carrier and particularly discloses a production method of heat-resistant spheroidal graphite cast iron for a fuel inlet housing. The production method comprises a material preparation process, a smelting process, a spheroidizing process, an inoculating process and a casting process. The heat-resistant spheroidal graphite cast iron for the gas inlet housing comprises the following components in percentage by weight: 3.00 to 3.40% of C, 3.60 to 4.00% of Si, 0.30 to 0.60% of Mn, not greater than 0.050% of P, not greater than 0.020% of S, 0.010 to 0.030% of Re, 0.020 to 0.060% of Mg, 0.40 to 0.70% of Mo, and the balance of iron. The heat-resistant spheroidal graphite cast iron for the gas inlet housing, produced by the method, is high in high-temperature strength and has oxidation resistance, anti-growth resistance and other heat-resistant performances.
Description
Technical field
The present invention relates to the production method of spheroidal graphite cast iron, is specifically the production method of a kind of planet carrier with spheroidal graphite cast iron.
Background technology
Along with the variation of China's energy structure, wind power technology progressively the reduction of ripe, cost and national policy the promotion of factor such as vigorously support, following domestic installed capacity of wind-driven power speedup is remarkable.Planet carrier is as a key component of wind power generating set, must guarantee that having enough intensity bears suffered environmental influence, yet due to the increase along with casting section thickness, the graphite form of ductile cast iron casting and matrix can worsen, therefore prior art need to reach by the thermal treatment guarantee nodular cast iron planetary supporter foundry goods in later stage the requirement of mechanical property aspect, but thermal treatment has brought complicated operation, energy consumption is large, cost is high, the yielding problem of foundry goods, and the planet carrier mechanical property that prior art adopts the as cast condition mode of production to obtain is poor.
Summary of the invention
Technical problem to be solved by this invention is, overcome the shortcoming of above prior art: provide the production method of a kind of simple to operate, energy consumption is little, cost is low planet carrier with spheroidal graphite cast iron, overcome the phenomenons such as the graphite form that the heavy section ductile iron foundry goods slowly brings due to speed of cooling is poor, matrix is thick, make the planet carrier that adopts spheroidal graphite cast iron of the present invention to produce under as cast condition there is excellent mechanical property.
Technical solution of the present invention is as follows: the production method of spheroidal graphite cast iron for a kind of planet carrier comprises burden process, melting operation, nodularization operation, breeds operation and cast operation; Described planet carrier spheroidal graphite cast iron, the weight percent of its composition is controlled as follows: C 3.40%～3.70%, Si 2.0%～2.2%, Mn≤0.4%, P≤0.03%, S≤0.02%, Cu 0.4%～1.0%, and Sb 0.006%～0.015%, and Re 0.01%～0.02%, Mg 0.03%～0.05%, and surplus is iron;
In described nodularization operation, employing is poured method and is carried out nodularization, and nodulizing agent is rare earth magnesium ferrosilicon alloy, and add-on is 0.80%～1.0% of iron liquid gross weight, and strengthens the flow that iron liquid pours the nodularization bag, makes every 7000kg iron liquid complete spheroidizing reacion in 90s.
As preferably, described planet carrier spheroidal graphite cast iron, the weight percent of its composition is controlled as follows: C 3.60%～3.70%, and Si 2.0%～2.2%, Mn≤0.2%, P≤0.02%, S≤0.02%, Cu 0.8%～1.0%, Sb 0.008%～0.01%, Re 0.01%～0.015%, and Mg 0.03%～0.035%, and surplus is iron.
In described melting operation, adopt cupola furnace-electric furnace double melting.
Described breeding in operation, breeding number of times is controlled at 2～4 times, as adopt the Multi inoculation technology, and while tapping a blast furnace, adopt 75 ferrosilicon nucleating agents to be bred, granularity is 3-8mm, add-on is 0.2～0.6% of iron liquid weight, before cast, adopt the Si-Ca-Ba nucleating agent to carry out current-following inoculation, granularity is 0.2-1mm, and add-on is 0.1% of iron liquid weight, and adopt 75 ferrosilicon inoculant blocks to carry out mould cavity inoculation, add-on is 0.08% of iron liquid weight.
In described cast operation, teeming temperature is controlled at 1290 ℃～1315 ℃.
The invention has the beneficial effects as follows: the present invention adopts cupola furnace-electric furnace double melting, effectively raise the purity of original iron melt, adopt micro-alloying technology to carry out the melting processing, add the alloy that promotes that perlite forms in iron liquid, finally make foundry goods body mechanical property reach the performance requriements of the attached casting test block of EN-1563 (2011) EN-GJS-700-2, improve the overall performance of foundry goods.
The present invention's employing is poured method and is carried out nodularization, nodulizing agent is selected rare earth magnesium ferrosilicon alloy, flow owing to having strengthened in the nodularization process that iron liquid pours the nodularization bag, the spheroidizing reacion time is completed in 90s, improved the specific absorption of magnesium and rare earth, strengthened sweetening effectiveness, correspondingly reduced the add-on of nodulizing agent, the nodulizing agent add-on is controlled between 0.80%～1.00%, thereby the residual rare earth in iron liquid and residual magnesium content are controlled to low scope, residual rare earth is controlled at 0.01%～0.02%, residual magnesium content 0.03%～0.05%, pass through the method, in purifying molten iron and refinement graphite, the pearlitic structure that promoted pearlitic formation and refinement.
The present invention adopts the Multi inoculation technology, while tapping a blast furnace, adopt 75 ferrosilicon nucleating agents to be bred, granularity is 3-8mm, add-on is 0.2～0.6% of iron liquid weight, before cast, adopt the Si-Ca-Ba nucleating agent to carry out current-following inoculation, granularity is 0.2-1mm, and add-on is 0.1% of iron liquid weight, and adopt 75 ferrosilicon inoculant blocks to carry out mould cavity inoculation, add-on is 0.08% of iron liquid weight.Solve foundry goods because wall thickness is large, speed of cooling is slow, the long graphite form caused of eutectic solidification time is poor, the phenomenons such as decaying spheroidisation with this.
The nodular cast iron planetary supporter that adopts planet carrier of the present invention to adopt the as cast condition mode of production to produce with spheroidal graphite cast iron, characteristics with difficult of deformation, the phenomenons such as the graphite form that thick and large section casting parts slowly brings due to speed of cooling is poor, matrix is thick have been overcome simultaneously, make nodular cast iron planetary supporter there is excellent mechanical property, and greatly extended the work-ing life of nodular cast iron planetary supporter.
Embodiment
Below by embodiment, the present invention is described in further detail, but the present invention not only is confined to following examples.
Adopt method of the present invention to produce the 3300T planet carrier, this planet carrier is the marine Large-scale Wind Turbines key parts of 3 megawatts, product weighs 5 tons, maximum physical dimension φ 1560mm * 1100mm, thickest surpasses 100mm, by the control to melting technology, spheroidization and inoculation processing, pouring technology, pouring cast part.Attached casting standard test block (70mm * 105mm * 180mm) and overproof test block 150mm * 150mm * 150mm on foundry goods.Finally test block and foundry goods body are detected.
Embodiment mono-
Adopting the pig iron, foundry returns, steel scrap, ferrosilicon, ferromanganese, electrolytic copper, antimony slab is feed proportioning, adopt cupola furnace-electric furnace double melting, employing is poured method and is carried out nodularization, nodulizing agent is rare earth magnesium ferrosilicon alloy, add-on is 0.85% of iron liquid gross weight, and strengthen the flow that iron liquid pours the nodularization bag, spheroidizing reacion is completed in 68s; Adopt the Multi inoculation technology, while tapping a blast furnace, adopt 75 ferrosilicon nucleating agents to be bred, granularity is 3-8mm, add-on is 0.2～0.6% of iron liquid weight, before cast, adopt the Si-Ca-Ba nucleating agent to carry out current-following inoculation, granularity is 0.2-1mm, and add-on is 0.1% of iron liquid weight, and adopt 75 ferrosilicon inoculant blocks to carry out mould cavity inoculation, add-on is 0.08% of iron liquid weight; Finally make the iron liquid that the one-tenth by following weight percent is grouped into: C 3.52%, and Si 2.13%, and Mn 0.26%, and P 0.023%, and S 0.009%, and Cu 0.68%, and Sb 0.012%, and Re 0.013%, and Mg 0.038%, and surplus is iron.Iron liquid is standing to 1311 ℃, pouring cast part, cast planet carrier foundry goods body and standard and overproof attached casting test block.
Planet carrier foundry goods body and attached casting test block are carried out to Performance Detection, the results are shown in Table 1.
Table 1 planet carrier foundry goods body and attached casting test block performance test results
| Title | Crucial wall thickness mm | Tensile strength MPa | Yield strength MPa | Unit elongation % | Hardness HB |
| 70mm * 105mm * 180mm standard test block | 70 | 851 | 550 | 4.4 | 298 |
| The overproof test block of 150mm * 150mm * 150mm | 150 | 749 | 475 | 3.9 | 252 |
| The foundry goods body | 300 | 742 | 457 | 3 | 215 |
| The Europe superscript standard | 60＜t≤200 | ≥650 | ≥380 | ≥1 | 210～305 |
Embodiment bis-
Adopting the pig iron, foundry returns, steel scrap, ferrosilicon, ferromanganese, electrolytic copper, antimony slab is feed proportioning, adopt cupola furnace-electric furnace double melting, employing is poured method and is carried out nodularization, nodulizing agent is rare earth magnesium ferrosilicon alloy, add-on is 0.90% of iron liquid gross weight, and strengthen the flow that iron liquid pours the nodularization bag, spheroidizing reacion is completed in 60s; Adopt the Multi inoculation technology, breed number of times and be controlled at 4 times, comprise mould cavity inoculation and current-following inoculation; Finally make the iron liquid that the one-tenth by following weight percent is grouped into: C 3.58%, and Si 2.09%, and Mn 0.31%, and P 0.028%, and S 0.011%, and Cu 0.73%, and Sb 0.011%, and Re 0.014%, and Mg 0.041%, and surplus is iron.Iron liquid is standing to 1309 ℃, cast planet carrier foundry goods body and standard test block and overproof test block.
After foundry goods is cooling, planet carrier foundry goods body and test block are carried out to Performance Detection, the results are shown in Table 2.
Table 2 planet carrier foundry goods body and attached casting test block performance test results
| The test block title | Crucial wall thickness mm | Tensile strength MPa | Yield strength MPa | Unit elongation % | Hardness HB |
| 70mm * 105mm * 180mm standard test block | 70 | 836 | 512 | 3.0 | 295 |
| The overproof test block of 150m * 150mm * 150mm | 150 | 746 | 485 | 4.1 | 252 |
| The foundry goods body | 300 | 729 | 508 | 3.2 | 213 |
| The Europe superscript standard | 60＜t≤200 | ≥650 | ≥380 | ≥1 | 210～305 |
Embodiment tri-
Adopting the pig iron, foundry returns, steel scrap, ferrosilicon, ferromanganese, electrolytic copper, antimony slab is feed proportioning, adopt cupola furnace-electric furnace double melting, employing is poured method and is carried out nodularization, nodulizing agent is rare earth magnesium ferrosilicon alloy, add-on is 0.90% of iron liquid gross weight, and strengthen the flow that iron liquid pours the nodularization bag, spheroidizing reacion is completed in 64s; Adopt the Multi inoculation technology, breed number of times and be controlled at 3 times, comprise mould cavity inoculation and current-following inoculation; Finally make the iron liquid that the one-tenth by following weight percent is grouped into: C 3.60%, and Si 2.12%, and Mn 0.2%, and P 0.02%, and S 0.009%, and Cu 0.8%, and Sb 0.01%, and Re 0.011%, and Mg 0.035%, and surplus is iron.Iron liquid is standing to 1305 ℃, pouring cast part.
After foundry goods is cooling, foundry goods body and test block are carried out to Performance Detection, the results are shown in Table 3.
Table 3 foundry goods body and attached casting test block performance test results
| The test block title | Crucial wall thickness mm | Tensile strength MPa | Yield strength MPa | Unit elongation % | Hardness HB |
| 70mm * 105mm * 180mm standard test block | 70 | 826 | 491 | 4.6 | 292 |
| The overproof test block of 150m * 150mm * 150mm | 150 | 729 | 432 | 3.6 | 248 |
| The foundry goods body | 300 | 733 | 461 | 3.3 | 216 |
| The Europe superscript standard | 60＜t≤200 | ≥650 | ≥380 | ≥1 | 210～305 |
Embodiment tetra-
Adopting the pig iron, foundry returns, steel scrap, ferrosilicon, ferromanganese, electrolytic copper, antimony slab is feed proportioning, adopt cupola furnace-electric furnace double melting, employing is poured method and is carried out nodularization, nodulizing agent is rare earth magnesium ferrosilicon alloy, add-on is 0.85% of iron liquid gross weight, and strengthen the flow that iron liquid pours the nodularization bag, spheroidizing reacion is completed in 75s; Adopt the Multi inoculation technology, breed number of times and be controlled at 3 times, comprise mould cavity inoculation and current-following inoculation; Finally make the iron liquid that the one-tenth by following weight percent is grouped into: C 3.55%, and Si 2.11%, and Mn 0.36%, and P 0.019%, and S 0.010%, and Cu 0.75%, and Sb 0.010%, and Re 0.013%, and Mg 0.039%, and surplus is iron.Iron liquid is standing to 1305 ℃, cast planet carrier foundry goods body and attached casting standard test block (70mm * 105mm * 180mm) and overproof test block 150mm * 150mm * 150mm.
After foundry goods is cooling, foundry goods body and test block are carried out to Performance Detection, the results are shown in Table 4.
Table 4 foundry goods body and attached casting test block performance test results
| The test block title | Crucial wall thickness mm | Tensile strength MPa | Yield strength MPa | Unit elongation % | Hardness HB |
| 70mm * 105mm * 180mm standard test block | 70 | 791 | 474 | 4.3 | 295 |
| The overproof test block of 150m * 150mm * 150mm | 150 | 765 | 510 | 3.8 | 255 |
| The foundry goods body | 300 | 747 | 486 | 2.8 | 217 |
| The Europe superscript standard | 60＜t≤200 | ≥650 | ≥380 | ≥1 | 210～305 |
Claims (5)
1. the production method of a planet carrier use spheroidal graphite cast iron, comprise burden process, melting operation, nodularization operation, breed operation and cast operation; It is characterized in that: described planet carrier spheroidal graphite cast iron, the weight percent of its composition is controlled as follows: C 3.40%～3.70%, Si 2.0%～2.2%, Mn≤0.4%, P≤0.03%, S≤0.02%, Cu 0.4%～1.0%, and Sb 0.006%～0.015%, and Re 0.01%～0.02%, Mg 0.03%～0.05%, and surplus is iron;
In described nodularization operation, employing is poured method and is carried out nodularization, and nodulizing agent is rare earth magnesium ferrosilicon alloy, and add-on is 0.80%～1.0% of iron liquid gross weight, and makes every 7000kg iron liquid complete spheroidizing reacion in 90s.
2. the production method of spheroidal graphite cast iron for planet carrier according to claim 1, it is characterized in that: described planet carrier spheroidal graphite cast iron, the weight percent of its composition is controlled as follows: C 3.60%～3.70%, and Si 2.0%～2.2%, Mn≤0.2%, P≤0.02%, S≤0.02%, Cu 0.8%～1.0%, Sb 0.008%～0.01%, Re 0.01%～0.015%, and Mg 0.03%～0.035%, and surplus is iron.
3. the production method of spheroidal graphite cast iron for planet carrier according to claim 1, is characterized in that: in described melting operation, adopt cupola furnace-electric furnace double melting.
4. the production method of spheroidal graphite cast iron for planet carrier according to claim 1 is characterized in that: described breeding in operation, and breed number of times and be controlled at 2～4 times.
5. the production method of spheroidal graphite cast iron for planet carrier according to claim 1, it is characterized in that: in described cast operation, teeming temperature is controlled at 1290 ℃～1315 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310377244.7A CN103484754B (en) | 2013-08-27 | 2013-08-27 | The production method of spheroidal graphite cast iron for planet carrier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310377244.7A CN103484754B (en) | 2013-08-27 | 2013-08-27 | The production method of spheroidal graphite cast iron for planet carrier |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103484754A true CN103484754A (en) | 2014-01-01 |
| CN103484754B CN103484754B (en) | 2015-08-12 |
Family
ID=49825342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310377244.7A Active CN103484754B (en) | 2013-08-27 | 2013-08-27 | The production method of spheroidal graphite cast iron for planet carrier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103484754B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104195423A (en) * | 2014-09-24 | 2014-12-10 | 山东宏马工程机械有限公司 | High-carbon low-silicon niobium-containing cast iron brake disc and preparation method thereof |
| CN104928563A (en) * | 2015-06-17 | 2015-09-23 | 邵阳富鑫实业有限公司 | Heat-resistant ductile iron resistant to aluminum liquid oxidation and manufacturing method thereof |
| CN104988381A (en) * | 2015-07-17 | 2015-10-21 | 江苏吉鑫风能科技股份有限公司 | Large-section cast ferrite nodular cast iron and preparation method thereof |
| CN106011602A (en) * | 2016-08-03 | 2016-10-12 | 日月重工股份有限公司 | Nodular cast iron used for marine diesel engine bodies, and preparation method thereof |
| CN106086615A (en) * | 2016-08-15 | 2016-11-09 | 合肥江淮铸造有限责任公司 | A kind of balance axle intermediate support and casting technique |
| CN115041634A (en) * | 2022-03-27 | 2022-09-13 | 宁波拓铁机械有限公司 | Casting method of wind power planet carrier casting |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002317219A (en) * | 2001-04-23 | 2002-10-31 | Tokyo Tekko Co Ltd | Production method for spheroidal graphite cast iron product as-cast |
| KR20080035160A (en) * | 2006-10-18 | 2008-04-23 | 현대자동차주식회사 | High strength and high oxidation resist hi silicon ferritic cast iron |
| CN101497956A (en) * | 2009-03-09 | 2009-08-05 | 无锡一汽铸造有限公司 | Big section ferrite magnesium iron and preparation technique thereof |
| CN102965567A (en) * | 2012-11-22 | 2013-03-13 | 日月重工股份有限公司 | Casting thick large-section pearlite nodular cast iron and casting method thereof |
-
2013
- 2013-08-27 CN CN201310377244.7A patent/CN103484754B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002317219A (en) * | 2001-04-23 | 2002-10-31 | Tokyo Tekko Co Ltd | Production method for spheroidal graphite cast iron product as-cast |
| KR20080035160A (en) * | 2006-10-18 | 2008-04-23 | 현대자동차주식회사 | High strength and high oxidation resist hi silicon ferritic cast iron |
| CN101497956A (en) * | 2009-03-09 | 2009-08-05 | 无锡一汽铸造有限公司 | Big section ferrite magnesium iron and preparation technique thereof |
| CN102965567A (en) * | 2012-11-22 | 2013-03-13 | 日月重工股份有限公司 | Casting thick large-section pearlite nodular cast iron and casting method thereof |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104195423A (en) * | 2014-09-24 | 2014-12-10 | 山东宏马工程机械有限公司 | High-carbon low-silicon niobium-containing cast iron brake disc and preparation method thereof |
| CN104928563A (en) * | 2015-06-17 | 2015-09-23 | 邵阳富鑫实业有限公司 | Heat-resistant ductile iron resistant to aluminum liquid oxidation and manufacturing method thereof |
| CN104928563B (en) * | 2015-06-17 | 2016-05-18 | 邵阳富鑫实业有限公司 | A kind of anti-aluminium liquid oxidation heat-proof nodular cast iron and manufacture method |
| CN104988381A (en) * | 2015-07-17 | 2015-10-21 | 江苏吉鑫风能科技股份有限公司 | Large-section cast ferrite nodular cast iron and preparation method thereof |
| CN106011602A (en) * | 2016-08-03 | 2016-10-12 | 日月重工股份有限公司 | Nodular cast iron used for marine diesel engine bodies, and preparation method thereof |
| CN106086615A (en) * | 2016-08-15 | 2016-11-09 | 合肥江淮铸造有限责任公司 | A kind of balance axle intermediate support and casting technique |
| CN115041634A (en) * | 2022-03-27 | 2022-09-13 | 宁波拓铁机械有限公司 | Casting method of wind power planet carrier casting |
| CN115041634B (en) * | 2022-03-27 | 2023-07-18 | 宁波拓铁机械有限公司 | Casting method of wind power planet carrier casting |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103484754B (en) | 2015-08-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103194660B (en) | Manufacturing method of low-temperature ferrite nodular cast iron material | |
| CN102965567B (en) | Casting thick large-section pearlite nodular cast iron and casting method thereof | |
| CN103484754B (en) | The production method of spheroidal graphite cast iron for planet carrier | |
| CN108624807B (en) | Cast high-pearlite high-creep-rate vermicular graphite cast iron and preparation method thereof | |
| CN103602878B (en) | High tough spheroidal graphite cast iron preparation method | |
| CN101519708B (en) | Production method of spheroidal graphite cast iron with high tenacity and corrosion resistance | |
| CN101363097A (en) | Low-temperature impact resistant as-cast ductile iron with big section and production method thereof | |
| CN104060157B (en) | A kind of hypereutectic high-chromium white cast iron and preparation method thereof | |
| CN107177711A (en) | A kind of smelting technology of thin-walled Ferrite nodular iron casting | |
| CN101603142A (en) | A kind of high-intensity high-tenacity ductile cast iron casting and preparation method thereof | |
| CN103757172A (en) | Method for preparing nodular cast iron | |
| CN105441782A (en) | Ductile iron casting and manufacturing method thereof | |
| CN101768691B (en) | Productive technology of short flow of structure type cast iron part | |
| CN104878275A (en) | Production technology for ductile iron casting with high strength and high ductility | |
| CN103088251B (en) | A kind of spheroidal graphite cast iron and heat treating method thereof | |
| CN103014388A (en) | Large-tonnage low-cost ultraclean melting method of producing Inconel690 alloy | |
| CN102965566A (en) | Raw material composition of marine knife gate valve ductile iron casting and its production method | |
| CN102373364B (en) | Wind-power equipment casting and manufacturing method thereof | |
| CN101343711A (en) | Method for producing nodular cast iron planetary supporter | |
| CN102534090B (en) | Preparation method of-60 ℃ low-temperature impact nodular cast iron | |
| CN101525677A (en) | Production method of high-strength grey cast iron for automobile fittings | |
| CN102660657A (en) | Low-cost production process for as-cast high-elongation nodular cast iron | |
| CN102851571B (en) | A kind of low-temperature-resistance high-toughness spheroidal graphite cast iron and preparation method thereof | |
| CN102260767A (en) | Method for producing minus 40 DEG C low temperature casting-state nodular graphite cast iron with large cross section | |
| CN103725949A (en) | Method for producing high-Ni austenite ductile iron exhaust pipe |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |