The factor that affects quality of small-sized and baric solder and answer measure

13MPa, acetylene pressure 0.

11MPa, aerobic discharge 216 M3/h, acetylene discharge 412 M3/h, heat time 4 Min 20 S. (2) heater number HH2012. (3) heat at that time in the process, blaze noise is unusual, from time to tome separate out of oily account other people, 3 Min controls course head surface to begin to submit fused form, upset is forced to shift to an earlier date. 1. 2 rupture analysis (1) visual examination welding line ruptures the line sees graph 1, fracture surface configuration sees a picture 2. Fracture surface divides an area, the head is flowing area for the most part, break a division for twinkling below. Twinkling breaks an area to see clear chevron pattern, chevron is most advanced point to course head flowing area and twinkling break an area to intersect place. (2) microcosmic examine to fall in optical microscope, cannot distinguish constituent feature. Scanning observes flowing area, twinkling breaks area organization to be fine pearlite below electric lens. The observation below scanning report lens has the hole that smoother facet and size differ and grain on flowing area, see a picture 3. Undertake to flowing area can chart analysis, did not see foreign matter element. Twinkling breaks an area to be accurate cleavage fracture surface, see graph 4, can chart analysis did not see composition deviation. 3) ruptures case study causes blaze because of acetylene quality problem unusual, make heat gradient of the temperature when rail is unusual, upset is stopped ahead of schedule, the melt state that course head institute forms has the area seam with very narrow periphery only in surface layer. Region of partition of course head greater part did not form metallic key union (not solder is appeared) , below outside force action, head of welding line course not solder is in craze fully, expand downward, rupture quickly. 2. Beijing breaths out a line (long bank line) part of bottom of baric solder course is small collapse phenomenal processing. On May 1, 2003, long bank the line is small-sized and baric when solder solders, discover heater heats to stop to grow course to solder after the effect is unusual and examine solder test specimen. 2. 1 first time tries solder weld time is HH2016; of number of heater of 2 days of;U75V 60 Kg/m; inputted 1 ～ in May 2003 aerobic pressure 0155 MPa, input acetylene pressure 0.

13M/a, output oxygen pressure 0.

13M/a, output acetylene pressure 0.

12M/a, aerobic discharge 2.

7 M3/h, acetylene discharge 4.

Each test specimen of 2 M3/h; is recorded alone: 1# weld time is down cave in for the horn end course of 9 Min (serious) , the horn end course of 8 Min 10s (of 2 # weld time is down cave in serious) , the horn end course of 6 Min 30 S (of 3 # weld time is down cave in serious) , (Note: ? The lid makes? of buy of Zi of pancreas money knock smooth with a rake.

38M/a) , the horn end course of 4# weld time 5 Min 54 S (is down cave in serious) , solder is over force of internal pressure of bottle of the acetylene after 3 # test specimen is 0.

9M/a, horn of bottom of course of 6 Min 44 S (of 5 # weld time is down cave in serious, does end face of welding line course measure Wen Wei 1 260 ℃ ) (the: that note ① ? Lose? of buy of Zi of knock of money of pancreas of large bamboo hat.

2M/a, ② : 1Acetylene of 5 # of # ～ is Harbin chemical industry 2 factories are made, same the outfit that approve fill. ) . Result of drop hammer test (peen tall 314 M) . 1 # drop hammer experiments 2 times hammer is attacked did not break second hammer of;3 # 2 to attack did not break strike off of second hammer of;5 # 2, did not see weld defects, fracture surface grain is normal. 2 # static turn experiments to press 1 350 KN to did not break;4 # static turn to experiment to press 1 460 KN to was not broken instead instead. 2. 2 try solder the 2nd times; acetylene was weld time on May 3, 2003 2 factories control Harbin chemical industry, for new rail of HH2016; of number of heater of; of outfit of a batch of fill divides weld time for 60 Kg/mU75 V; outside, the others is the same as 4 Min 55 S of weld time of;6# of test specimen of 5# of 1# ～ , does 4 Min 50 S (of normal;7# weld time note welding line exterior: ? Screen Mou? turns welding line) 4 Min 57 S of;8# weld time. Test result. 6 # drop hammer experiments 2 times hammer is attacked did not break;7 # drop hammer to experiment 2 times hammer is attacked did not break;8 # drop hammer to experiment 2 times hammer is attacked did not break. Cut a mouth to interrupt, did not see weld defects. Accordingly, the quality of acetylene gas and solder closely related quality. The acetylene quality of different manufacturer differs bigger, the quality of different lot number also has same manufacturer difference. Solder to assure quality, the acetylene that should use large company to produce is angry, when changing batch, should do first solder experiment. 2, solder work environment to soldering quality is affected bank case study of broken end of solder of boreal line atmospheric pressure breathed out bureau canal on November 28, 1999 inside bank north goes up place of line K28 + 200m, the head of baric solder solder that inserts rail of adhesive bonding insulation ruptures. Welding line ruptures the line sees graph 5, fracture surface configuration sees a picture 6. Weld time on October 29, 1999, rail type is Russia M76B, 65 Kg/m, time to break on November 28, 1999, solder parameter: ? You Ren goes straight towards? Min 20 S falling into oblivion, the others is the same as U75 V. The place solders to insert rail of adhesive bonding insulation, 4 solder head solders in all when circuit blocks, the solder head that rupture is head of the last solder. The air temperature before soldering is left and right sides of 6 ℃ , change suddenly to the weather when course, fresh gale drops in temperature, ℃ of extent close 8, solder exercise proceed, still use the knife that push protruding to remove tumor. Right now upset implement did not protect pressure. Because drop in temperature suddenly, long rail generation is larger pull stress, when pushing protruding to remove tumor, welding line temperature is in above of 900 ℃ , strength of welding line union is very right now low, upset implement did not protect pressure, cause welding line by local (crackle source) pull open, in the wheel concussion and rail stress action fall, solder head ruptures quickly. In air temperature (course is lukewarm) inferior when or drop in temperature faster when, should use protect pressure push protruding or remove tumor with the gun that remove tumor. 3, different steel is planted the diverse demand 　 to heater (1) began to solder 2002 PD3 (U75V) , solder at first when test specimen, did not undertake any adjustment to be being used at trying 2 heater of solder, when these 2 heater use rail of U74 of Yu Angang U71Mn, Bao Gang to solder, solder quality is good. Try solder for the first time 15 test specimen, discover horn of bottom of course of 4 test specimen has injury wave when ultrasonic flaw detection. Classics drop hammer experiments, root of;1 of 2 hammer strike off in these 4 test specimen 2 times hammer attacks root of;1 of 2 hammer strike off to was not broken. Via fracture surface examination, horny part has had the test specimen of hammer strike off to burn a phenomenon below course, burn left and right sides of area 2 Mm2 too, of 2 hammer strike off, the horn on course bottom also has had burn, but the area is lesser. Try solder the 2nd times when 5 test specimen, flaw detection still discovers horn of bottom of a course has, via drop hammer the experiment checks fracture surface, had had truly burn blemish. (2) burn too to heat temperature of ministry of the current political situation is exorbitant and those who cause. The heat conduction rate of this likelihood and U75 V and U71Mn, U74 has certain difference to concern. Via studying an analysis, the 3 fire aperture that the decision manages part of heater course bottom (two side in all 6) the diameter is contractible (make an appointment with contractible 10 %) , in order to reduce the hot input of pair of course bottom horn. Try solder the 3rd times 5 test specimen, flaw detection did not discover course bottom horn has drawback, fall the experiment had not seen burn wait for blemish. Hind again solder 10 test specimen, all did not discover flaw of course bottom character. In beginning to breath out 324 connect that line spot solders in Beijing in April 2002, did not discover bottom horn has had welding line course to burn blemish when flaw detection. (3) the rail that different steel plants has diverse demand possibly to heater, accordingly, if steel is planted,change, answer heater or heat parameter tries to adjust. CNC Milling