CN103589900A - Wear-resistant copper alloy material and casting method thereof - Google Patents
Wear-resistant copper alloy material and casting method thereof Download PDFInfo
- Publication number
- CN103589900A CN103589900A CN201310501689.1A CN201310501689A CN103589900A CN 103589900 A CN103589900 A CN 103589900A CN 201310501689 A CN201310501689 A CN 201310501689A CN 103589900 A CN103589900 A CN 103589900A
- Authority
- CN
- China
- Prior art keywords
- wear
- electrolytic copper
- copper alloy
- cual10ni
- alloy material
- 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
- Conductive Materials (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
The invention relates to a CuAl10Ni wear-resistant copper alloy material and a casting method thereof, wherein total seven raw materials, including an aluminum-copper alloy, a nickel plate, pure iron, electrolytic copper, metal manganese, hexachloroethane and cullet, are employed; the CuAl10Ni wear-resistant copper alloy material is obtained through the steps of stove charging, melting, sodium fluoroaluminate doping and sand mold test sample casting, casting molding and the like; and the mechanical properties of the obtained CuAl10Ni wear-resistant copper alloy material reach the following standards: yield strength B0.2: more than or equal to 270N/mm<2>; tensile strength Bb: more than or equal to 600N/mm<2>; elongation sigma5: more than or equal to 12%; and Brinell hardness HBW: more than or equal to 140; the wear-resistant copper alloy material is specially used for manufacture of the positioning guide sleeve of the air spring of a rail transit vehicle, and has excellent comprehensive mechanical properties, and extremely high abrasive resistance and corrosion resistance; and the service life of the wear-resistant copper alloy material is twice as long as that the service life of the traditional ZCuAl9Mn2(S) material.
Description
Technical field
The present invention relates to a kind of CuAl10Ni wear-resistant copper alloy material and castmethod thereof; The CuAl10Ni wear-resistant copper alloy material and the castmethod thereof that particularly relate to a kind of rail traffic vehicles pneumatic cushioning location guide pin bushing product.
Background technology
Traditional rail traffic vehicles pneumatic cushioning location guide pin bushing is to adopt GB GB/T1176-1987 casting al-bronze (ZCuAl9Mn2) manufacture, exist comprehensive mechanical performance poor, wear no resistance and shortcoming that erosion resistance is poor.
Summary of the invention
The object of the invention is to overcome above-mentioned shortcoming and defect, provide that a kind of tensile strength and yield strength are high, wear resistance and anticorrosive good, elongation is high and a kind of CuAl10Ni Cu alloy material and the castmethod thereof of long service life;
The object of the invention is to realize by following technical proposal: a kind of castmethod of CuAl10Ni wear-resistant copper alloy material, is characterized in that described CuAl10Ni wear-resistant copper alloy material completes melting and casting by following raw-material weight proportion batching and processing method and step:
The weight proportion of each described raw material is:
Aluminum bronze intermediate alloy 15～26 weight parts, nickel plate 4～8 weight parts,
Pure iron 3～6 weight parts, electrolytic copper 60～80 weight parts,
Manganese metal 1～2 weight part, hexachloroethane 0.3～0.6 weight part,
Glass cullet 2～6 weight parts;
Wherein, aluminum bronze intermediate alloy, is 50% containing Al, and all the other are Cu;
In nickel plate, contain Ni >=99.5%;
Pure iron is containing Fe >=99%;
Manganese metal is containing Mn >=99%;
CuAl10Ni wear-resistant copper alloy material Chemical Composition is as follows:
Cu≥76％, Al 9.5～11.0％, Ni 4.0～6.5％,
Fe 3.5～5.5％, Mn 1.0～3.0%；
Each described step is:
(1), shove charge, the melting equipment of CuAl10Ni wear-resistant copper alloy is medium-frequency induction furnace, the electrolytic copper of above-mentioned weight proportion, nickel plate and pure iron are packed into and be preheated in bolarious crucible, shove charge method is: first block electrolytic copper is layered on to crucible bottom, block electrolytic copper quantity is 7 ~ 10, then nickel plate and pure iron are layered on block electrolytic copper layer, more remaining block electrolytic copper is layered on nickel plate and pure iron layer, finally long strip shape electrolytic copper is covered with to crucible periphery;
(2), fusing, rapid melting after shove charge, 1200 ~ 1250 ℃ of temperature of fusion, after electrolytic copper, nickel plate and pure iron all melt, stir aluminium alloy, add by weight ratio again manganese metal, limit edged stirs, and after manganese metal adds, adds a little electrolytic copper cooling, while being cooled to thick paste, start to add by weight ratio aluminum bronze intermediate alloy; Wherein, add the method for aluminum bronze intermediate alloy to be: block-by-block adds, often adding one, fully stir, is exothermal reaction process because adding the process of aluminum bronze intermediate alloy, as aluminium alloy temperature rises highlyer, add electrolytic copper cooling, concrete operations principle is: low temperature adds aluminum bronze intermediate alloy, fully stirs, the electrolytic copper of cooling use is standby electrolytic copper, and the electrolytic copper of cooling use enters the necessary preheating in stokehold;
(3), mix sodium fluoroaluminate and casting sand mould sample, after aluminum bronze intermediate alloy adds, when aluminium alloy temperature reaches 1200 ~ 1250 ℃, separately add sodium fluoroaluminate 0.3 ~ 0.5%, then fully stir, after having stirred, carry out conventional skimming, casting sand mould sample and air content check, air content check as defective, is used bell jar to divide to be by weight ratio pressed into hexachloroethane for 2 times and carries out refining degasification;
(4), casting, air content after the assay was approved, is poured into a mould, and adopts horizontal centrifuge casting, 400 ~ 500 revs/min of rotating speeds, 1100 ~ 1200 ℃ of teeming temperatures in casting process, add glass cullet to cover by proportion scale in the copper alloy liquid of casting ladle.
(5), the CuAl10Ni wear-resistant copper alloy material mechanical property that obtains by aforesaid method, can reach following standard: yield strength б
0.2>=270N/ ㎜
2, tensile strength б
b>=600N/ ㎜
2, elongation σ
5>=12%, Brinell hardness HBW>=140, this wear-resistant copper alloy material is specifically designed to produces rail traffic vehicles pneumatic cushioning location guide pin bushing product.
The CuAl10Ni wear-resistant copper alloy material obtaining by aforesaid method has the advantages such as wear resistance that comprehensive mechanical performance is good, high and erosion resistance.
Below by traditional ZCuAl9Mn2 (S) material and the contrast of CuAl10Ni (Li) mechanical property of materials:
Table 1
| alloy designations | tensile strength б b | yield strength б 0.2 | elongation σ 5 | brinell hardness HBS |
| zCuAl9Mn2 (S) | 390 | / | 20 | 85 |
| cuAl10Ni (Li) | 600 | 270 | 12 | 140 |
In sum, this wear-resistant copper alloy material is specifically designed to manufactures rail traffic vehicles pneumatic cushioning location guide pin bushing, has good comprehensive mechanical performance, high wear resistance and erosion resistance, can extend one times its work-ing life.
Embodiment
The castmethod of mono-one kinds of CuAl10Ni wear-resistant copper alloy materials of embodiment, described in it is characterized in that
CuAl10Ni wear-resistant copper alloy material completes melting and casting by following raw-material weight proportion batching and processing method and step:
The weight proportion of each described raw material is:
Aluminum bronze intermediate alloy 20 weight parts, nickel plate 5.3 weight parts,
Pure iron 4.5 weight parts, electrolytic copper 69 weight parts,
Manganese metal 1 weight part, hexachloroethane 0.4 weight part,
Glass cullet 5 weight parts;
Wherein, aluminum bronze intermediate alloy, is 50% containing Al, and all the other are Cu;
In nickel plate, contain Ni >=99.5%;
Pure iron is containing Fe >=99%;
Manganese metal is containing Mn >=99%;
CuAl10Ni wear-resistant copper alloy material Chemical Composition is as follows:
Cu≥76％, Al 9.5～11.0％, Ni 4.0～6.5％,
Fe 3.5～5.5％, Mn 1.0～3.0%；
Each described step is:
(1), shove charge, the melting equipment of CuAl10Ni wear-resistant copper alloy is medium-frequency induction furnace, the electrolytic copper of above-mentioned weight proportion, nickel plate and pure iron are packed into and be preheated in bolarious crucible, shove charge method is: first block electrolytic copper is layered on to crucible bottom, block electrolytic copper quantity is 7 ~ 10, then nickel plate and pure iron are layered on block electrolytic copper layer, more remaining block electrolytic copper is layered on nickel plate and pure iron layer, finally long strip shape electrolytic copper is covered with to crucible periphery;
(2), fusing, rapid melting after shove charge, 1200 ~ 1250 ℃ of temperature of fusion, after electrolytic copper, nickel plate and pure iron all melt, stir aluminium alloy, add by weight ratio again manganese metal, limit edged stirs, and after manganese metal adds, adds a little electrolytic copper cooling, while being cooled to thick paste, start to add by weight ratio aluminum bronze intermediate alloy; Wherein, add the method for aluminum bronze intermediate alloy to be: block-by-block adds, often adding one, fully stir, is exothermal reaction process because adding the process of aluminum bronze intermediate alloy, as aluminium alloy temperature rises highlyer, add electrolytic copper cooling, concrete operations principle is: low temperature adds aluminum bronze intermediate alloy, fully stirs, the electrolytic copper of cooling use is standby electrolytic copper, and the electrolytic copper of cooling use enters the necessary preheating in stokehold;
(3), mix sodium fluoroaluminate and casting sand mould sample, after aluminum bronze intermediate alloy adds, when aluminium alloy temperature reaches 1200 ~ 1250 ℃, separately add sodium fluoroaluminate 0.3 ~ 0.5%, then fully stir, after having stirred, carry out conventional skimming, casting sand mould sample and air content check, air content check as defective, is used bell jar to divide to be by weight ratio pressed into hexachloroethane for 2 times and carries out refining degasification;
(4), casting, air content after the assay was approved, is poured into a mould, and adopts horizontal centrifuge casting, 400 ~ 500 revs/min of rotating speeds, 1100 ~ 1200 ℃ of teeming temperatures in casting process, add glass cullet to cover by proportion scale in the copper alloy liquid of casting ladle;
(5), the CuAl10Ni wear-resistant copper alloy material mechanical property that obtains by aforesaid method, reach following standard: yield strength б
0.2>=270N/ ㎜
2, tensile strength б
b>=600N/ ㎜
2, elongation σ
5>=12%, Brinell hardness HBW>=140, this wear-resistant copper alloy material is specifically designed to produces rail traffic vehicles pneumatic cushioning location guide pin bushing product.
The castmethod of 21 kinds of CuAl10Ni wear-resistant copper alloy materials of embodiment, is characterized in that described CuAl10Ni wear-resistant copper alloy material completes melting and casting by following raw-material weight proportion batching and processing method and step:
The weight proportion of each described raw material is:
Aluminum bronze intermediate alloy 25 weight parts, nickel plate 4 weight parts,
Pure iron 3 weight parts, electrolytic copper 65 weight parts,
Manganese metal 1.7 weight parts, hexachloroethane 0.3 weight part,
Glass cullet 4 weight parts;
Its casting technique and step are identical with embodiment mono-.
Embodiment tri-
A castmethod for CuAl10Ni wear-resistant copper alloy material, is characterized in that described CuAl10Ni wear-resistant copper alloy material completes melting and casting by following raw-material weight proportion batching and processing method and step:
The weight proportion of each described raw material is:
Aluminum bronze intermediate alloy 16 weight parts, nickel plate 4 weight parts,
Pure iron 4 weight parts, electrolytic copper 75 weight parts,
Manganese metal 1.5 weight parts, hexachloroethane 0.5 weight part,
Glass cullet 2 weight parts;
Its casting technique and step are identical with embodiment mono-.
Claims (2)
1. a castmethod for CuAl10Ni wear-resistant copper alloy material, is characterized in that described CuAl10Ni wear-resistant copper alloy material completes melting and casting by following raw-material weight proportion batching and processing method and step:
The weight proportion of each described raw material is:
Aluminum bronze intermediate alloy 15～26 weight parts, nickel plate 4～8 weight parts,
Pure iron 3～6 weight parts, electrolytic copper 60～80 weight parts,
Manganese metal 1～2 weight part, hexachloroethane 0.3～0.6 weight part,
Glass cullet 2～6 weight parts;
Wherein, aluminum bronze intermediate alloy, is 50% containing Al, and all the other are Cu;
In nickel plate, contain Ni >=99.5%;
Pure iron is containing Fe >=99%;
Manganese metal is containing Mn >=99%;
CuAl10Ni wear-resistant copper alloy material Chemical Composition is as follows:
Cu≥76％, Al 9.5～11.0％, Ni 4.0～6.5％,
Fe 3.5～5.5％, Mn 1.0～3.0%；
Each described step is:
(1), shove charge, the melting equipment of CuAl10Ni wear-resistant copper alloy is medium-frequency induction furnace, the electrolytic copper of above-mentioned weight proportion, nickel plate and pure iron are packed into and be preheated in bolarious crucible, shove charge method is: first block electrolytic copper is layered on to crucible bottom, block electrolytic copper quantity is 7 ~ 10, then nickel plate and pure iron are layered on block electrolytic copper layer, more remaining block electrolytic copper is layered on nickel plate and pure iron layer, finally long strip shape electrolytic copper is covered with to crucible periphery;
(2), fusing, rapid melting after shove charge, 1200 ~ 1250 ℃ of temperature of fusion, after electrolytic copper, nickel plate and pure iron all melt, stir aluminium alloy, add by weight ratio again manganese metal, limit edged stirs, and after manganese metal adds, adds a little electrolytic copper cooling, while being cooled to thick paste, start to add by weight ratio aluminum bronze intermediate alloy; Wherein, add the method for aluminum bronze intermediate alloy to be: block-by-block adds, often adding one, fully stir, is exothermal reaction process because adding the process of aluminum bronze intermediate alloy, as aluminium alloy temperature rises highlyer, add electrolytic copper cooling, concrete operations principle is: low temperature adds aluminum bronze intermediate alloy, fully stirs, the electrolytic copper of cooling use is standby electrolytic copper, and the electrolytic copper of cooling use enters the necessary preheating in stokehold;
(3), mix sodium fluoroaluminate and casting sand mould sample, after aluminum bronze intermediate alloy adds, when aluminium alloy temperature reaches 1200 ~ 1250 ℃, separately add sodium fluoroaluminate 0.3 ~ 0.5%, then fully stir, after having stirred, carry out conventional skimming, casting sand mould sample and air content check, air content check as defective, is used bell jar to divide to be by weight ratio pressed into hexachloroethane for 2 times and carries out refining degasification;
(4), casting, air content after the assay was approved, is poured into a mould, and adopts horizontal centrifuge casting, 400 ~ 500 revs/min of rotating speeds, 1100 ~ 1200 ℃ of teeming temperatures in casting process, add glass cullet to cover by proportion scale in the copper alloy liquid of casting ladle;
(5), the CuAl10Ni wear-resistant copper alloy material mechanical property that obtains by aforesaid method, reach following standard: yield strength б
0.2>=270N/ ㎜
2, tensile strength б
b>=600N/ ㎜
2, elongation σ
5>=12%, Brinell hardness HBW>=140, and be specifically designed to production rail traffic vehicles pneumatic cushioning location guide pin bushing product.
2. a kind of CuAl10Ni wear-resistant copper alloy material that the method for claim 1 is cast.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310501689.1A CN103589900B (en) | 2013-10-23 | 2013-10-23 | Wear-resistant copper alloy material and casting method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310501689.1A CN103589900B (en) | 2013-10-23 | 2013-10-23 | Wear-resistant copper alloy material and casting method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103589900A true CN103589900A (en) | 2014-02-19 |
| CN103589900B CN103589900B (en) | 2015-06-10 |
Family
ID=50080210
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310501689.1A Active CN103589900B (en) | 2013-10-23 | 2013-10-23 | Wear-resistant copper alloy material and casting method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103589900B (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104593629A (en) * | 2015-02-08 | 2015-05-06 | 浙江同诚合金铜管有限公司 | Copper alloy pipe fusion covering agent |
| CN104745861A (en) * | 2015-04-07 | 2015-07-01 | 江苏科技大学 | Nickel aluminum bronze plastic mould material and preparation method thereof |
| CN104745862A (en) * | 2015-04-09 | 2015-07-01 | 凯达铁建电气化铁路器材有限公司 | Copper alloy casting and casting method thereof |
| CN104862522A (en) * | 2015-04-24 | 2015-08-26 | 中国科学院宁波材料技术与工程研究所 | Nickel-aluminum bronze alloy and preparation method thereof |
| CN108193076A (en) * | 2017-12-13 | 2018-06-22 | 浙江灿根智能科技有限公司 | A kind of high temperature Vulcan metal and production method |
| CN109207789A (en) * | 2018-10-22 | 2019-01-15 | 扬州丰铜业有限公司 | A kind of military boats and ships anti-corrosive alloy material and preparation method thereof |
| CN111455211A (en) * | 2020-05-17 | 2020-07-28 | 安徽凯斯威精工科技有限公司 | High-corrosion-resistance and high-wear-resistance copper-nickel alloy material and preparation method and application thereof |
| CN115466862A (en) * | 2022-09-27 | 2022-12-13 | 同创普润(上海)机电高科技有限公司 | Smelting process of ultra-pure copper-aluminum alloy |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007117079A1 (en) * | 2006-04-11 | 2007-10-18 | K E & C Co., Ltd. | Lubricative copper alloy |
| CN102115835A (en) * | 2009-12-30 | 2011-07-06 | 倪志刚 | High-strength corrosion resistant copper alloy and preparation process thereof |
| CN102925743A (en) * | 2012-11-12 | 2013-02-13 | 宁波博威合金材料股份有限公司 | Lead-free wear-resistant copper alloy and preparation method thereof |
-
2013
- 2013-10-23 CN CN201310501689.1A patent/CN103589900B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007117079A1 (en) * | 2006-04-11 | 2007-10-18 | K E & C Co., Ltd. | Lubricative copper alloy |
| CN102115835A (en) * | 2009-12-30 | 2011-07-06 | 倪志刚 | High-strength corrosion resistant copper alloy and preparation process thereof |
| CN102925743A (en) * | 2012-11-12 | 2013-02-13 | 宁波博威合金材料股份有限公司 | Lead-free wear-resistant copper alloy and preparation method thereof |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104593629A (en) * | 2015-02-08 | 2015-05-06 | 浙江同诚合金铜管有限公司 | Copper alloy pipe fusion covering agent |
| CN104745861A (en) * | 2015-04-07 | 2015-07-01 | 江苏科技大学 | Nickel aluminum bronze plastic mould material and preparation method thereof |
| CN104745862A (en) * | 2015-04-09 | 2015-07-01 | 凯达铁建电气化铁路器材有限公司 | Copper alloy casting and casting method thereof |
| CN104862522A (en) * | 2015-04-24 | 2015-08-26 | 中国科学院宁波材料技术与工程研究所 | Nickel-aluminum bronze alloy and preparation method thereof |
| CN104862522B (en) * | 2015-04-24 | 2016-11-23 | 中国科学院宁波材料技术与工程研究所 | A kind of nickel aluminum bronze and preparation method thereof |
| CN108193076A (en) * | 2017-12-13 | 2018-06-22 | 浙江灿根智能科技有限公司 | A kind of high temperature Vulcan metal and production method |
| CN109207789A (en) * | 2018-10-22 | 2019-01-15 | 扬州丰铜业有限公司 | A kind of military boats and ships anti-corrosive alloy material and preparation method thereof |
| CN111455211A (en) * | 2020-05-17 | 2020-07-28 | 安徽凯斯威精工科技有限公司 | High-corrosion-resistance and high-wear-resistance copper-nickel alloy material and preparation method and application thereof |
| CN115466862A (en) * | 2022-09-27 | 2022-12-13 | 同创普润(上海)机电高科技有限公司 | Smelting process of ultra-pure copper-aluminum alloy |
| CN115466862B (en) * | 2022-09-27 | 2024-02-06 | 同创普润(上海)机电高科技有限公司 | Smelting process of ultra-high purity copper-aluminum alloy |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103589900B (en) | 2015-06-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103589900B (en) | Wear-resistant copper alloy material and casting method thereof | |
| CN103469109B (en) | A kind of shaping roll of graphitized steel material and manufacture method thereof | |
| CN102828063A (en) | Novel lead-free environment-friendly high-strength wear-resistant copper-base alloy bar and preparation method thereof | |
| CN101914708A (en) | Al-Fe-Cu alloy material and preparation method thereof | |
| CN110438390B (en) | Steel for petroleum pipeline valve body made of 280 mm-diameter large-size round bar and production method of steel | |
| CN102127666B (en) | Preparation method of rare earth aluminum alloy conductor | |
| WO2018072368A1 (en) | Rare earth-copper alloy glass mold and preparation method therefor | |
| CN107747066A (en) | Raw nano TiC ceramic particle In-sltu reinforcement casts high chromium hot die steel and preparation method thereof in one kind | |
| CN104388769A (en) | High-purity aluminum-silicon (Al-Si) intermediate alloy and production method thereof | |
| CN102127658A (en) | Method for preparing high-purity aluminum-vanadium intermediate alloy | |
| CN104313232A (en) | Alloy gray cast iron material for locomotive brake disc, and casting method of alloy gray cast iron material | |
| CN104789848A (en) | Smelting method for high-magnesium nodulizer and cored wire manufactured by adopting nodulizer as core | |
| CN104087766A (en) | Process for producing rare earth copper alloy | |
| CN103233094B (en) | Smelting process of high-strength alloy steel | |
| CN102286681A (en) | Aluminum silicon alloy brake hoop of elevator motor and manufacture method thereof | |
| CN103060525B (en) | Process for high pressure compaction of fluorite ball with sodium silicate as binder | |
| CN104178684A (en) | Smelting method of chromium-molybdenum-copper-nickel-tin-antimony low-alloy wear-resistant cast iron | |
| CN103146984B (en) | High-intensity gray pig iron inoculator and preparation method thereof | |
| CN103938088A (en) | A slab continuous casting method of an electric resistance alloy Cr20AlY | |
| CN104357708B (en) | A kind of Environmental Safety smelting process of high-performance nickelaluminium bronze | |
| CN105401063A (en) | As-cast malleable cast iron cylinder sleeve produced through centrifugal casting and production process of as-cast malleable cast iron cylinder sleeve | |
| CN106319337A (en) | Anti-cracking rare earth alloy cast iron glass mould material | |
| CN103664212B (en) | Castable refractory for tundish permanent layer and preparation method of permanent layer | |
| CN104233014A (en) | Alloy material for moving blade of axial compressor and preparation method of alloy material | |
| CN106244939A (en) | A kind of abrasion-proof backing block and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20160831 Address after: 412001 Hunan Province, Zhuzhou Shifeng District Tian Xin North Gate Patentee after: Zhuzhou Liancheng Group Casting Industry Co., Ltd. Address before: 412000 Hunan Province, Zhuzhou Shifeng District North Gate Tian Xin Liancheng group technology management department Patentee before: Liancheng Group Co., Ltd., Zhuzhou |