Pipeline of long gas transporting oil solders technical development and demand

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Summary: As the adjustment of the development of industry of our country energy and structure of the sources of energy, plumbing builds swift and violent development. Solder the crucial technology that the technology regards long energy of life transporting oil as plumbing construction, matter to cost of efficiency of project quality, construction, construction directly, and the sex of on the safe side during cop moves and economic benefits. In the light of long energy of life transporting oil plumbing solders the characteristic of construction, the article introduced conduit to solder systematically construction technology, choose principle and domestic and international current situation, basically include to solder material, solder equipment, solder method, welder art wait for a respect. Keyword: Oil gas conduit; Cop steel; Automatic solder; Preface is long be defeated by conduit to regard as remote the main kind that oil gas carries, as the adjustment of the development of industry of our country energy and structure of the sources of energy, plumbing builds swift and violent development. End by 2003, be defeated by 45865Km of length of accumulative total of oil gas conduit, house world the 6th; 2126 Km of 6525 Km of path of vitta of 21299 Km of conduit of 15915 Km of oily conduit of its Central Plains, natural gas, finished product, marine conduit. "Enrage on the west east be defeated " , " line of Ji Ning contact " , " second line of Beijing of short for Shaanxi Province " , " western conduit " wait for home large plumbing builds go into operation in succession or be about to finishing, the conduit that cross a state " in haing cop " also be about to finishing, reach with Russia neighbour, medium inferior the cop construction that waits for a country plans in insecurity all the time in. According to national program, to 2020, duct of our country oil gas reasonable, contact becomes cloth of main body part net, mutual allocate, the on the safe side, oil gas that covers countrywide main area manages a network, contented socioeconomy development and people life need. The annulus solder place in pipeline construction is the much hair position of invalidation accident, conduit solders the technology is the crucial technology that must ensure in construction, matter to a project directly not only solder efficiency of quality, construction and cost, and the sex of on the safe side during moving to cop and economic benefits also have main effect. Accordingly, begin plumbing solder technical research, rise solder technical level, it is contemporary the inevitable requirement of high grade, efficient construction. 1. The weldability of cop steel is measured to increase conduit to carry and drop a project cost, contented more and more slashing use condition requirement, large requirements, be able to bear or endure the steel of cop of excel in tenacity that high pressure, Bao Bi converts is development trend. Steel of cop of X70 of homebred excel in is in " enrage on the west east be defeated " use in the round in the project, x80 coulds there be in look forward to only at present try out succeeds on conduit. The Euramerican country such as Germany, Canada has been mixed in land ocean built cop of a lot of X80; The φ 1219mm × that company of pipeline of Canadian Trans Canada finished 1km 2002 14.

The X100 steel tube of 3mm experiments paragraph, 1 what Exxon Mobil company built X120 steel tube at was in Canada 2004.

6km experiments paragraph. [1] steel of cop of excel in tenacity belongs to low alloy excel in steel, low carbon or exceed mild microalloy to accuse steel rolling, used fine technology, microalloy steel technology, accuse make friends to accuse the advanced technique such as heat treatment of cold technology, deformation, this makes tubal material contains carbon the quantity is extremely low, clean spend tall, grain to refine, have taller obdurability and good weldability, solder especially sensitivity of cold crack of hot influence area is reduced greatly, tenacity of area of thick any crystalline substance rises substantially, the welder that suits energy of efficient, spread cables further art. However, new issue appears subsequently, if the high strenth of low carbon equivalent of mother capable person is changed,make cold crack from solder in heating up influence area to transfer welding line metal, the problem of local brittleness area in multilayer welding connect. Accordingly to steel of low alloy excel in, should note problem of cold crack of welding line metal. Solder to spread cables energy, must solder to its organization of hot influence area and tenacity undertake assess, should note the problem of local brittleness area of multilayer welding particularly. To new development exceed fine grain steel, the welder that should use high energy density, low hot input art will prevent to solder of grain of hot influence area be brought up overly. 2. Solder material solders the choice of material is long be defeated by conduit to solder a when want a consideration important facet, welding rod, welding wire, welding flux and protective gas include on broad sense, welding rod and welding wire are referred in particular to on narrow sense. [2] 2.

1 welding rod is long whole place is used to issue the low hydrogen to solder welding rod and tradition welding rod more before be defeated by conduit to solder to look with welding rod, its carry out a standard to be GB/T 5117-1995, GB/T 5118-1995, AWS A5.

1-91 and AWS A5.

5-96. To solder welding rod cent is two kinds below whole place: One kind is tall cellulose model (be based on content of cop steel C, S, P inferior, can consider to use) , this kind of welding rod solders technical properties is good, slaggy the quantity is little, and blow force bigger, prevented slaggy with molten iron next dripping, and bigger frit shows ability and rate of faster frit apply, in all sorts of positions bosseyed solder is double-faced shape the effect is good, comfortable at root solder and hot solder, have the representative BOHLER FOX CEL that produces like company of Austrian Bai Le (AWS A5.

1-91E6010) with BOHLER FOX CEL 85 (AWS A5.

5-96E8010, P1) the FLEETWELD 5P+ that company of Lincoln of welding rod, United States produces (AWS A5.

1-91E6010) with SHIELD ARC 70+ (AWS A5.

5-96E8010, G) welding rod, medium the SRE425G that boat heavy industry develops 725 times (AWS A5.

1-91E6010) , SRE505 (AWS A5.

5-96E7010, G) with SRE555 (AWS A5.

5-96E8010, G) welding rod. Another kind is iron pink low hydrogen below to welding rod, this welding rod is caky fluidity of fast, molten iron mixes speed wellability is good, complete when positional solder next not easily dripping, tenacity of metal of the welding line after solder crack resistance is good, good, comfortable at each below to solder, have the representative BOHLER FOX BVD 85 that produces like company of Austrian Bai Le (AWS A5.

5-96E8018-G) the LINCOLN LH D80 that company of Lincoln of welding rod, United States produces (AWS A5.

5-96E8018-G) welding rod. The low hydrogen to the tradition welding rod because its are complete locally to root solder when, stability of the general, difficulty that bring arc, electric arc differs technical properties, splatter bigger, the reverse side shapes poor, easy stoma, reason is used no longer commonly at present, solder with Yu Wei rush to repair and repair commonly among solder of fill lid side, have the representative CHE507GX(GB/T 5118-1995 E5015) that produces like Sichuan Atlantic company, CHE557GX(GB/T 5118-1995 E5515) . Norms of afore-mentioned welding rod of commonly used tall cellulose are Φ commonly 3.

2mm, Φ 4.

0mm, norms of iron pink low hydrogen welding rod is Φ commonly 4.

0mm, common norms of low hydrogen welding rod is Φ commonly 3.

2mm. Will tell commonly, σ 0.

5 (0.

2) ≤ 415MPa is defeated by artery of oily, conduit is defeated by water to solder optional choose tall cellulose welding rod undertakes each solder; Conduit transporting gas or σ 0.

Petroleum pipeline of 5 > 415Mpa artery solders can use solder of root of tall cellulose welding rod, hot solder + next low hydrogen compound craft to side of welding rod fill, lid. 2.

2 welding wire are long be defeated by cop to be sincere welding wire and medical core welding wire with welding wire cent two kinds. (Welding wire of sincere of 1) sincere welding wire basically has two kinds: One kind is used at burying arc solder, another kind is used at fusing extremely active gas protects solder. The solder that bury arc carries out a standard to have GB/T 5293-1999 with sincere welding wire, have low manganese welding wire, if H08A(is like the CHW-SG welding wire that Sichuan Atlantic company produces) cooperate welding flux of tall manganese fusion, use at the cop steel with mild steel and intensity inferior level to solder; In manganese welding wire, be like H08MnA, H10MnSi, cooperate welding flux of low fluorine of tall manganese tall silicon fusion to basically be used at cop steel to solder, can cooperate low manganese welding flux to be used at mild steel to solder; Tall manganese welding wire, if H08Mn2Si, H08Mn2SiA is used at cop steel to solder; Mn-Mo welding wire, be like H08MnMoA, HO8MnMoTiB, welding flux of the fluorine in the silicon in cooperating low manganese fusion, fluorine is alkaline model welding flux of agglomeration welding flux or silicon calcium agglomeration, basically spend the cop steel with higher level to solder with Yu Jiang. Welding wire diameter is in commonly 1.

6 ~ 6.

4mm limits less than. Active gas protects solder to carry out a standard to have GB/T 14947-1994, GB/T 8110-1995, AWS 5 with sincere welding wire.

18-93 and AWS 5.

The standard such as 28-96, the most commonly used welding wire has H08Mn2SiA (if be equivalent to GB/T 8110 ER49-1) , it has good welder art function, appropriate at soldering the cop steel of 500MPa of σ S ≤ . Should solder when intensity level fastens taller steel to plant, should choose to contain the welding wire of Mo, for example, homebred H10MnSiMo welding wire and executive beauty GB allow AWS 5.

18The JM-58 welding wire that the company of bright and beautiful peaceful of ER70S-G produces, BOHLER SG3-P welding wire and executive beauty GB allow AWS A5.

28The welding wire of JM-68 of bright and beautiful peaceful of ER80S-G. The norms of commonly used welding wire is φ 0.

9mm, φ 1.

0mm, φ 1.

2mm. (Welding wire of 2) medicine core in recent years, as long be defeated by cop to change directional development towards high strenth, large requirements, large wall, traditional manual solder solders the method already was soldered gradually by semi-automatic solder and automatic solder methodological place is replaced, use development with semi-automatic solder among them most rapid, to it and those who come is medical core welding wire be able to swift and violent development. Core welding wire can get medicine such attention and develop, a lot of characteristics with its oneself are not divided, expression is in: Frit apply rate is rapid, yield of solder deliver a child is high; Compare with photograph of solid core welding wire, electric arc of medical core welding wire is soft, splatter small, solder technical properties is good; Frit is deep big, shape beautiful; Integrated cost is low. Medical core welding wire differs by what way protects when soldering can divide the protection that it is gas medical core welding wire and protect medical core welding wire oneself, protect medical core welding wire oneself among them with its peculiar advantage is growing in be defeated by conduit wide application, executive standard has GB/T 17493-1998 and AWS A.

29-98. Have have T8-Ni1 representatively model (for example Φ of JC-29Ni1 of Tianjin Jin Qiao 2.

Φ of HOBART 81N1 of Hao Bai spy of 0mm welding wire, United States 2.

0mm welding wire) , T8-Ni2, T8-K6 (Lincoln NR207 Φ 2.

0mm welding wire) wait, performance of operation of whole place of this kind of welding wire is good, frit apply rate is rapid, tenacity of welding line metal is good at the same time, but welding line metal is bulky below as welded columnar the occurrence that brilliant organizes, make tenacity of concussion of metal of its welding line is between as welded and heat treatment, multilayer welding and only way have very big difference between solder. Because this uses T8 model when from protection welding wire solders, should control strictly solder quantity of normative parameter, hot input, solder second and the ply of every solder layer. 2.

What body length of 3 protection gas is defeated by conduit is automatic solder to use carbon dioxide gas to protect solder and oxidisability gas mixture to protect solder more, the gas that uses namely is CO2, CO2+Ar or CO2+Ar+O2. Among them inert gase (like Ar) in extremely fused the action in aeriform protection solder is the air all round an electric arc and fused metal the platoon leaves, lest the harmful composition in air affects the stability of electric arc and liquid state metal,be polluted. Other is not inert gase (like CO2, O2) also can use as extremely fused the protective gas of aeriform protection solder. Although,its premise is these gas can with be produced by protective liquid metal certain metallurgy reaction, but soldering the consequence that the condition can create to make these react in the process is unapt go to solder in couples the harm of contact. If use CO2 to regard protection as gas, although soldering,the CO2 in the process decomposes an O2 and CO2 below the high temperature of electric arc, make Fe oxidation generates FeO and likelihood to bring about air hole then, but this one bad influence can join the deoxidization element such as right amount Si, Mn to give through be in welding wire solve. Consider to discover, protective gas composition and discharge shape to welding line have certain effect, composition and discharge are different, oxygen is contained to differ in welding line, welding line shapes different, blemish odds is different also. If undertake STT gas protection uses pure CO2 when solder root solder,regard protection as gas and discharge slants big when, because CO2 decomposes condensation of welding line of action of absorption of heat to accelerate, molten iron fluidity becomes poor, cause openly welding line easy form ridge body, in subsequently solder its cave in the process part is easy cause the defect such as incomplete fusion, slag inclusion, rear welding line is easy cause false frit appearance, this one problem is in temperature of the environment that apply solder is inferior highlight particularly with the expression when line capabilities is inferior. In addition, because welding line is fast condensation is easy the stoma in bringing about welding line. If if current of ameliorable iron of 80%) of ~ of Ar(85 of + of CO2(15 ~ 20%) uses a sex,use CO2+Ar gas mixture, obtain good welding line to shape, mother capable person and welding line transfer good and oxygen is contained in welding line the amount is small, tenacity of welding line concussion is good. When this are choosing to protect aeriform composition and flow, should bring in order to take seriously. 2.

The matchs characteristic, welding flux metallurgy performance of the type that welding flux basically considers when 4 welding flux choose welding flux, welding flux and welding wire and technical properties. In addition content of phosphor of the granuality of welding flux, water content, mechanical field trash, sulfur also should give consideration. From the angle consideration that improves tenacity of welding line metal, can choose tall alkalinity welding flux. But should notice, exceed some when alkalinity when critical value, raise alkalinity to be able to bring about welding line tenacity to drop again, because solder to cop steel,this basically is when, the demand is higher solder speed, be in especially thick board do not open the groove, requirement that does not leave gap to fall, technical properties is exasperate, occurrence stoma of welding line surface, hemp is nodded, field trash of the oxide in welding line is apparent grow in quantity, bring about tenacity to drop. Accordingly, logical choice welding flux, have important sense to raising welding line tenacity. 3. Solder the power source development as electronic technology and contemporary control technology, digitlization inversion solders the main way that power source is development of arc solder power source. Its bulk small, weight is light, energy-saving province material, and control performance is good, trends is answered fast, come true easily solder the real time control of the process, very large dominant position is had on function. At the same time compositive the digitlization inversion that the intelligence such as technology of network of expert system, ambiguous control, nerve controls a method solders power source, can realize centralize adjustment, to soldering the inaccuracy that appears in the process decides an element to make real time handle, assure to solder steadily process and solder quality. Domestic times, abstruse too the inversion welder that waits for welder to produce manufacturer to roll out soft switch control already successfully, the technology such as much arc of double silk double arc, double silk odd arc, much silk also has application in abroad. Now, power source of welder of our country inversion already fashioned 4 acting products: generation is the inverter that gives priority to power parts of an apparatus with SCR of silicon controlled rectifier; The 2nd generation is transistor inverter; The 3rd generation is inverter of field effect canal; The 4th generation is IGBT inverter, its inversion frequency is tall, saturation pressing is reduced, power comsumption is small, efficiency is tall, without noise, with before 3 generation inverter photograph is compared, the advantage is clearer. But, at present construction site still uses IGBT inversion welder rarely. General dc welder is used when cellulose welding rod solders, appear easily when small electric current arc, stick, electric arc is flabby wait for a problem. Low hydrogen welding rod is inferior to the requirement of arc solder equipment, device of common dc arc solder can satisfy a requirement. The welder that manual arc welding uses in pipeline construction has the DC-400 of American LINCOLN company, the XMT-304 of American MILLER company, the ZX7-400B of company of Beijing age group, jinan the ZX7-400ST that abstruse great-grandfather manages. When from protection medical core welding wire solders, the DC-400 direct current source that can choose American LINCOLN company + LN-23P sends filar plane, additional the XMT304 direct current source of MILLER company + S-32P sends filar plane, tang Wang DC-400+LINCOLN LN-23P sends filar machine to also can offer an alternative. When CO2 gas protects solder root solder, power source of the STT that the welder that can choose is LINCOLN company inversion + LN-742 sends filar plane, the welder of ULTRA FLEX PULSE 350 of flying Matt company + ULTRAFEED 1000 sends filar plane. 4. Solder at present domestic minister of foreign affairs transports method and fixture conduit is commonly used solder the method basically has: (1) manual solder, include arc welding of coating welding rod (SMAW) , by hand solder of arc of tungsten pole argon (TIG) ; (2) semi-automatic solder, include to fuse extremely gas protects semi-automatic solder [include active gas to protect STT(Surface Tension TransferTM) semi-automatic solder, semi-automatic extremely fused argon arc solder (MIG) , semi-automatic active gas protects solder (MAG) , protect arc welding of medical core welding wire oneself (FCAW) ; (3) fuse extremely active gas protects automatic solder (AW) . In addition, still have bury arc automatic solder (SAW) , resistance welding, glitter is right solder (FBW) etc. Our country is in enrage on the west east after be defeated by plumbing main with protecting medical core welding wire oneself semi-automatic solder is mixed fuse extremely active gas protects automatic solder to give priority to. 4.

Solder of handiwork of 1 manual solder basically points to welding rod arc welding and handiwork solder of arc of tungsten pole argon. (Arc welding of 1) welding rod has agile and handy, adaptability to wait for a characteristic by force, improve of technical properties ceaselessly as a result of welding rod at the same time, efficiency of its frit apply, mechanical function still can satisfy the need that current conduit builds, blame meantime solders the application when filling solder is wider. Welding rod is cellulose welding rod and low hydrogen welding rod, its fall to be mixed to solder on to solder the organic union of two kinds of methods reachs the root solder adaptability with cellulose good welding rod to be below a lot of circumstances still is other solders methodological place cannot replace. (2) is manual solder of arc of tungsten pole argon solders quality is good, back does not have solder broken bits, use commonly have the facility such as imports and exports of station field compressor, ball valve, and tubal diameter lesser, wall is large thinner craft conduit, the installation that puts type fillet weld solders. Before solder of requirement of method of solder of arc of tungsten pole argon undertake groove clears strictly, solder the beard in the process has windbreak measure. 4.

2 semi-automatic solder protect medical core welding wire oneself namely semi-automatic solder and CO2 gas protect semi-automatic solder, they are to fall to solder method. (1) protects medical core welding wire oneself this technology is in semi-automatic solder the library Shan line 1996 applies at first in plumbing, wait for the promotion in plumbing to apply in Sudan, Lan Chengyu, acerbity Ning Lan subsequently. This kind solders methodological operation is agile, the environment gets used to ability strong, solder frit apply efficiency is tall, solder quality is good, the solderer masters easily, solder joint rules and forms of classical poetic composition is tall, it is current method of the serious stuff in domestic plumbing, solder that cover a range. (2) CO2 gas protects semi-automatic solder as solder the improvement of power source character, through controlling frit drop and electric arc configuration, CO2 enrages those who protect solder to splatter the problem is solved basically already, important role is acted in beginning to solder in conduit, the application that is like welder of STT CO2 inversion. This kind solders methodological operation is agile, the solderer masters easily, strong to different groove adaptability, solder quality is good, solder efficiency is tall, solder talk is smooth, but solder the effect that the process suffers surrounding air speed is bigger. Solder of STT semi-automatic root maintains clearance of speak or sing alternately to agree equably in Cheng of opposite of requirement nozzle group, will be in otherwise hind the blemish such as incomplete fusion of brim of groove of the generation in path of the fill of foreword, solder that cover a range, slag inclusion. 4.

3 automatic solder are automatic solder applicable is mixed at root solder the fill, solder that cover a range. (Method of automatic root solder uses solder of 1) automatic root automatic inside welder or outside welder is bosseyed solder is double-faced shape. A.

Inside welder " enrage on the west east be defeated " what use in plumbing is automatic inside welder is the conduit root solder that provides way in the light of Φ 1016mm solders private plane, produce for British NOREAST company respectively inside welder and PIW3640 of bureau of conduit of Chinese oil natural gas inside welder. Its characteristic is applicable limits tubal way narrow, equipment invests bigger, but solder efficiency is very tall, 70 seconds or so are made an appointment with when the solder of steel tube root of Φ 1016mm needs. Because be,undertake soldering inside steel tube, solder the effect that surrounding air speed suffers in the process is less, if pursue,1 is shown. Graph 1 conduit is automatic inside welder solders process B.

Automatic outside welder is bosseyed solder is double-faced shape a solder is bosseyed solder is double-faced shape the CWS that root solder equipment basically is Italian PWT company.

02NRT automatic outside welder, and the STT power source of American LINCOLN company matchs automatic outside welder. Automatic outside welder is bosseyed solder is double-faced shaping root solder equipment was solved need not the bosseyed solder of rear gasket is double-faced problem of figuration root solder, root solder ply is amounted to 4.

5 m m , of the welder inside outclass solder ply (1 ~ 1.

2 m m ) , solder efficiency is tall, 8 minutes or so are made an appointment with when the solder of steel tube root of Φ 1016mm needs. Because use aeriform protection, solder the process is sensitive to surrounding air speed, the due and windbreak canopy windbreak measure when construction. (2) is automatic outside the PAW-2000 that welder conduit bureau produces outside welder, if the graph is shown 2 times, its characteristic is to solder frit is deep even, the groove width that can solder is bigger, but normally requirement groove angle is more than 13 ° , in order to because solder,avoid 2 PAW-2000 of electric arc graph outside welder and interface of mother capable person are lesser and the groove brim incomplete fusion that bring about. The APW- Ⅱ that produces with academy of project of company of group of Chinese oil natural gas automatic outside welder function close. [3] what British NOREAST company produces is automatic outside welder, the MOW-1 that Canadian RMS company produces automatic outside welder and M-300 of American CRC company automatic outside welder, its characteristic is to come true easily 5 - of the small groove angle of 8 ° solder operation, groove face fusion is good, but solder frit is deep inhomogenous, the groove width that can solder does not exceed 10mm normally, make sure in the place that admire solder welding line shapes hard otherwise. The CWS that Italian PWT company produces.

02NRT automatic outside welder, its characteristic is to solder frit is deep even, the groove width that can solder is bigger, and come true easily 5 - of the small groove angle of 8 ° solder operation, groove face fusion is good. 5. Welder art 5.

1 solder conduit of contact groove form solders the groove type that construction uses normally is API standard 30 ° V groove, suit manual solder. But to steel tube of large requirements, large wall, such soldering amount of metal of stuff of contact groove type is large, labor intensity is high, and do not agree with the soldering of automatic solder, normally semi-automatic solder uses 23 ° V groove, automatic solder is used narrow space is complex groove type. 5.

The purpose of warm-up of the temperature between 2 warm-up and layer is the stress state that carries material of slow down mother and the cooling rate that lower root solder line will prevent root ministry cold crack. Conduit solders diameter of rule of change of performance of the intensity of the capable person of mother of Lv of take an examination of warm-up temperature limits of construction, organization, canal and wall are large, and solder the element such as the quantity containing hydrogen of material. To the multilayer welding of large wall steel tube, consider to control the temperature between solder path layer to control the cooling rate that seams an area nearly even. The temperature between the layer is average with warm-up temperature close. Below the premise that avoids the close overheat that seam an area, the temperature between taller layer can prevent the generation of the cold crack when multilayer welding. 5.

Of energy of wiring of solder of energy of 3 solder wiring need to consider class status of mother capable person integratedly certainly, solder stuff kind, right coating (medical core, welding flux) state of the warm-up before metallurgy reaction and protective gas protect the influence of the effect, solder, layer, and the position that apply solder, solder second, the transition that ply of every solder layer, welding line shapes to drip with frit the element such as the form. 5.

4 postheat processing and heat treatment cop solder the postheat processing after construction does not undertake solder commonly and heat treatment. But when construction of high to be in cold area, when having bigger effect hard with control of the temperature between the layer when the warm-up before solder, be necessary to soldering contact takes certain postheat and heat treatment step, assure to solder the organization of contact and function. 5.

5 other solder in conduit should consider susceptive of place of thick steel tube of high strenth, big wall is exterior in construction process the influence that stress action brings. Should consider humidity of environmental temperature, environment and surrounding air speed to solder to differring at the same time methodological influence, adopt necessary step to assure to solder quality. 6.

Look into in front introduced domestic conduit to solder applied current situation of the technology, soldering the material, method, craft and equipment technology difference that uses respect and abroad is less and less, automatic solder technology popularizes application basically already. But of home solder material is satisfied at manual solder more, own research and development, production is not worth automatic welding wire and semi-automatic solder material, still need an import partly quite. At the same time home solders the function of material also remains to improve, range of products changes inadequacy. Soldering power source respect, home abstruse too, times welder had large area to apply, but still cannot apply in that way like Lincoln welder at present extensive; The home of power source of automatic root solder that is used at render still does not have production. Solder, laser assists electron beam of deep recently frit extremely fused aeriform protection arc welding is on conduit application have revolutionary progress. Could there be in look forward to as steel of domestic X80 cop the success of conduit solders, x100 of steel of more advanced cop and X120 also will apply on domestic pipeline construction before long. Of cop steel class rise, be opposite necessarily solder technical demand is higher and higher, especially to soldering material is mixed solder the performance demand of equipment, because this home is soldering,technical respect still has very large promotion space, to soldering the demand of material and equipment also can increase further. CNC Milling