One, overview aircrew bear press component and conduit to solder the actor bad of quality is the influence generates electricity one of keys that equipment safety runs. The conduit in the spot, most diameter is lesser, cannot undertake double-faced solder, how to ensure the quality of welding line, it is a crucial question. The butt welding to mouth of solder of thin wall conduit was seamed before 2000, use gasket of ministry of arc welding of oxygen acetylene gas welding, welding rod, root to encircle welding rod arc welding and tungsten commonly extremely argon arc solder undertakes soldering, at that time the confine as a result of solderer technology level, the resentment of be afraid of difficulty of together with solderer and suffer solder a variety of reasons such as the position and operation space limitation, TIG solders the promotion application of new technology encounters resistance, bear press component and pipeline leak accident to happen often, serious menace moves to the safe stability of aircrew. Small 2000 when repairing change a canal high again 64 butt welding mouth, use oxygen acetylene gas welding, mouth of gas welding solder runs a the middle of a month to produce leak accident 3 times continuously in aircrew, the reason is the heating surface pipe that uses oxygen acetylene gas welding to solder, quantity of heat is not centered, area of contact hot influence is large, overheat is serious, plasticity and tenacity are poor. If solderer operation is undeserved, the rate of blaze evacuation bath is too rapid, produce shrinkage cavity easily still. Accordingly, when boiler moves, often be in occurrence leakage in the connect of mouth of solder of gas welding of heating surface pipe. This kind of accident is in charge of in the heating surface previously in soldering, already happened many cases, for this, solder to 4 kinds methodological test is compared, the result makes clear among them TIG solders technical advantage is the biggest. Reason decides to begin from August 2000, abide by make solder the principle of craft, to pipe of boiler heating surface the overhaul solders attempt sex uses arc of TIG complete argon to solder technology, solder mouth nondestructive detects percent of pass amounts to 95% above, satisfactory result is gotten in application. Accordingly, progressively in 4 years of time later promotion uses the medium such as transmission steam, water, oily, gas bear control conduit share, the effect is very apparent, come 6 years, because solder the heating surface of quality happening " cartridge igniter " the accident dropped 100% , ensured cycle of the safety of aircrew, firm fixed length moves. In view of this, TIG solders the technology solders as a kind new technology and new technology, soldering metallic stuff side has advantaged with irreplaceable advantage, have main technique and economic value, this kind solders in answering to overhaul installation to solder in the power station, the technology causes more to inspect and achieve greater progress again. 2, conduit solders technical development general situation and system of current situation power generate electricity each the enterprise is when installation and overhaul boiler, be in charge of to the Bao Bi of this kind of small diameter, from 20 centuries arrive before founding a state 70 time, use oxygen acetylene gas welding generally, the part uses welding rod arc welding. Boiler manufactory to mouth of this kind of solder, outside using osculatory solder except the part, also use oxygen acetylene gas welding and welding rod arc welding in great quantities. Use oxygen acetylene gas welding to solder pipe of boiler heating surface, quantity of heat is not centered, area of contact hot influence is large, overheat is serious, plasticity and tenacity are poor. If solderer operation is undeserved, the rate of blaze evacuation bath is too rapid, produce shrinkage cavity easily still. Accordingly, when boiler moves, often be in occurrence leakage in the connect of mouth of solder of gas welding of heating surface pipe. 3, TIG solders the metallic stuff of solder of advantage ① TIG is unlimited actually on breed and amount, they are mixed in appearance and form, area there are a lot of characteristics on strength of other dimension, union and performance characteristics, all these decided TIG solders the technology is in the there are a lot of outstanding effects in soldering application of metallic stuff. ② Ar is one of the stablest inert gase, protective effect is good. Gas protection replaced broken bits protection, welding line does not have broken bits completely. Inert gase argon is mixed in bath one is formed to close all round electric arc air current, prevent the outside effectively of harmful gas invade, acquire high quality thereby solder contact. Electric arc of ③ TIG solder suffers the compression of argon air current and cooling effect, electric arc concentration, can make sure solder of ministry of welding line root is appeared, area of contact hot influence is small, weldment is out of shape reach crackle inclination is little. Special apply to solder the steels with big liability of empty temper by dipping in water. ④ Ar not dissolve at the metal, do not produce reaction with the metal, reason won't appear commonly alloying element burns caustic. TIG welding line is particularly pure, place solder pipe does not have solder broken bits inside contact canal. Welding line quality is better than oxygen acetylene gas welding and welding rod arc welding. ⑤ Ming Hu solders, bath clarity is visible, the operation masters easily, yi Shi shows automation. ⑥ argon air current erodes again to weld zone region action, make solder contact cooling rate is accelerated, can improve the organization of contact and performance, the remains after can reducing weldment solder is out of shape. ⑦ Ar is only atomic gas, thermal capacity is small, heat conduction efficiency is low, quantity of heat is used up little, stable to electric arc combustion is very advantageous, although be below small electric current and the requirement that grow arc, electric arc still very stable, the operation is convenient, welding line quality is controlled easily, the whole place that applies to position of trail pipe difficult solder solders. Solder as a result of TIG solder quality is good, the operation is apt, in last few years, already became each to generate electricity the commonly used method that the enterprise accepts heating surface pipe in the solder when installation and overhaul boiler. In the spot overhaul condition falls, suffer solder the position and operation space limitation, the technique that uses generally is arc welding of welding rod of TIG solder render cover a range or use solder of arc of TIG complete argon. 4, bear control pipeline solder power system each unit solders bear control pipeline, basically used render of welding rod arc welding in the past and cover the butt joint method of the face, ministry of easy generation root not solder is appeared, the blemish such as slag inclusion, safe to aircrew moving menace is very big. Power system ever produced solder mouth to break off for many times, blow up accident, analyse accident reason, much as serious as ministry of welding line root not solder is concerned fully. In last few years power station aircrew of abroad solders in construction in, uniform to solder mouth demand is overall solder is appeared. Be in our country, already applied at soldering in power system promotion of high-pressured aircrew advocate steam, advocate water supply, reheat paragraph, cold paragraph, couplet box socket and conduit of steam engine system. 1, the TIG of conduit solder mouth solders technical ① solders equipment and appliance: Solder system of power source, welding torch, air feed, cooling system and solder the part such as control system. ② power source: TIG solders power source has communication and dc two kinds. Alternating current source is used at soldering magnesium and aluminium and its alloy, its alloy. Solder copper and carbolic steel, alloy steel, titanium and its alloy, its alloy all use direct current source. ③ welding torch: TIG solder welding torch wait for composition by button of clip of nozzle, tungsten pole, lead, tracheal, conduit, control, it is removing clip to run electrode, conduction current, carry argon gas and control are overall the action of working system, welding torch has from Leng Shihe water-cooled two kinds. 2, solder material: ? So not " ㄎ of of be used to of herd of lever appearance so scar of of ㈦ money raiseds paths between fields Tang of Ru herd rare ＂ so? commonly used tungsten has cerium extremely tungsten pole and thorium tungsten extremely. ② Ar:AContain more or less in R 02, n, CO: Reach the impurity such as moisture, the effect that protects to Ar has certain effect. Chemistry of stuff of place solder metal heals lively, the influence heals big. Solder different metal, it is different to the requirement of Ar purity. : of ③ stuff stuff? So not " grandma of Mei of another name for Jiangxi Province raiseds paths between fields Ru herd disrelishs welding wire of solder of arc of of frame of street of haying hamper of fan of Kang Tu of have diarrhoea lever, argon: Solder of render of conduit solder mouth is recommended use Ø2. 5 Mm welding wire. Useful also to the small diameter tube with particularly thin tube wall Ø2.
Of 0 Mm welding wire. B, but frit annulus has dawdle shape and rectangle two kinds. When solder of render of conduit solder mouth, assemble in clearance of speak or sing alternately, classics tungsten extremely electric arc heats fused form render welding line together with seam of two side groove. 3, solder craft should acquire excellent render welding line, except often should maintain solder equipment is in whack to reach choose solder suitably outside material, still need to adopt sound technology, and by technical level taller eligible solderer is undertaken operating. ① blocks wind and arc of clean requirement argon to solder the place must want to have the reliable measure that block wind, prevent the draught inside the canal, lest affect protective result. The oil inside stuff stuff and limits of 10-15mm of side of nozzle inside and outside, corrupt, ferruginous etc sundry should keep clear of clean, till show metallic burnish. When necessary, usable acetone is cleaned.
When wall of ② solder mouth fills argon to protect pair of mild steel and mouth of solder of conduit of low alloy refractory steel to undertake render of argon arc solder, argon protection need not be filled inside the canal; And reach mouth of solder of conduit of austenite stainless steel to tall alloy refractory steel, must fill argon protection. Fill argon to have two kinds of kind: One kind is to rectify a conduit to be full of argon, apply to the pipe with very small diameter, if stainless steel sampling is in charge of. The conduit with bigger diameter is used normally but dissolve paper or installation piston at solder mouth inside two side pipe, form a small air chamber to fill argon inside air chamber only. To prevent argon from a large number of leak in clearance of speak or sing alternately, asbestine of built-in in clearance circuit needs before solder rope or stick on circuit adhesive plaster, solder the part that solder uses be a hindrance to at any time in the process is pulled. When render solder ends, pull out quickly argon is tracheal fill good hole eye. Regard air chamber as the wall but dissolve paper is when solder mouth heat treatment by cremate ashes, eliminate along with water after hydraulic experiment. Wall is filled inferior throughput changes along with air chamber size and flat rate, protect in order to achieve already good, because flow is too large,do not send again and cause welding line inside sunken advisable. ③ groove form and size of dimension groove shape and tubal end assemble clearance the quality to welding line and impact of bend of root ministry crackle are very big. Form of commonly used groove has V form, U form, double V form to wait, tubal end is assembled stay have certain space. Figure of department of extreme of tungsten of figure of department of ④ tungsten extreme is stabilized to electric arc and welding line figuration has very big effect, relatively good figure is wear of tungsten pole extreme obtuse angle or contain flat-roofed taper. Can make electric arc combustion stable so, arc column diffuses decrease, to weldment heat concentration. Tungsten extreme ministry should be not ground too pointedly, lest touch,break cause welding line to place tungsten limitation. ⑤ solder mouth assembles mouth of solder of spot welding pipe to adopt clamping apparatus to assemble commonly, secure in root ministry spot welding. To horizontal solder mouth, the pipe of diametical ≤ 60mm can be in only spot welding of position of flat position welding 1 place, length makes an appointment with L0, 20mm; Diameter > the pipe of 159mm, reach spot welding of position of vertical position welding in flat position welding commonly 3 place, solder dot grows 50mm of about 30 ～ . The tack welding check the number of perpendicular solder mouth and water flat position welding are identical, spot welding position decides according to particular case. What use welding wire, solder craft and the requirement to solderer technology level all with when soldering formally identical. Welding line of solder of arc of argon of the warm-up before ⑥ solder is purer, and low hydrogen, general need not warm-up, but be like when winter construction or large wall pipe fitting solder not warm-up, the possibility arises crackle on render welding line. Can inspect diameter or wall parameter of warm-up of thick different make choice of. ⑦ only then solder and stop solder only then need to send argon ahead of schedule when solder, lag needs to break argon when stopping solder, suffer with protecting welding line to avoid all round air enroach on. Bring arc to want to undertake inside groove. When adopting contact inspection to bring arc, the operation wants firm, light, fast, prevent tungsten extreme to the ministry burns caustic to be touched and produce the phenomenon that place tungsten. Some of welding wire should be added more when stopping solder to receive arc, cram arc hole. Bring electric arc to groove brim again extinguish arc: Collect arc and contact place mass often poorer, solder the process should avoid to stop arc as far as possible, reduce contact amount. ⑧ fills silk silk is filled to operate a way inside operation method, it is welding wire extends a canal from clearance of speak or sing alternately inside, electric arc burns on the groove outside the canal, welding wire is fused inside the canal, whole solder process section undertakes. This operation method has two advantages: It is render seams rear and even ground slightly raised, the part that admire solder won't appear inside sunken; 2 it is special apply to position of difficulty of boiler close tube bank to solder. But when the operation, gap of requirement speak or sing alternately is big, use Ø2.
When 5mm welding wire, clearance amounts to 3mm above, the amount that fill silk is larger, solder rate is corresponding the ground is some slower. When filar law is being filled to solder outside, solder mouth assembles clearance lesser, operation demand is steady and be in charge of quickly to small diameter large wall, clearance is equal to or be less than welding wire diameter a bit, the welding torch when the operation basically is not done transverse swing. Large to big diameter wall is in charge of, clearance is more than welding wire diameter a bit, the welding torch when the operation swings. In the operation perfect case falls, figuration of the reverse side of render welding line is very even also, and respect solder place not inside sunken. This kind of advantage that operates a way is the quantity that fill silk less, solder rate is rapid. But to soldering the mouth of solder of boiler close tube bank with particularly difficult position, sometimes outside the operation that fill silk is quite difficult, criterion appropriate is used inside, outside the method that the photograph that fill silk combines undertakes soldering. Solder when boiler tube bank, quality of the place between the canal assures the hardest, apply solder by two solderers semmetry commonly. 4, other note ① solders appliance must not demolish all basically gets power be geared to the needs of the job in the process, lest outside force makes craze of render welding line. When ② render solder is about to end, answer to observe condition of figuration of welding line the reverse side carefully, discover the problem is handled in time. After whole render solder ends, should have visual examination, have magnetic particle flaw detection or chromatic examination when necessary. Check qualification hind to undertake welding rod arc welding covers a range in time, prevent to produce crackle. Welding line of render of solder of ③ argon arc is smaller, accordingly, arc welding of follow-up welding rod of L layer should use small diameter welding electrode. 5, welder of epilogue application TIG art, can solve welding line root not solder shows an issue, raise welding line nondestructive to examine percent of pass, assure effectively to solder quality, apply effect ideal. Application, promotion deserves in power station installation and overhaul. CNC Milling
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