Esi kplᴐe ɖo, Hangao Tehc (Seko mɔ̃wo) ayi edzi akplɔ wò be nàse kuxi siwo ate ŋu ado mo ɖa le welding ƒe ɖoɖoa me gɔme eye wòakpe ɖe ŋuwò nàxe mɔ ɖe kuxi mawo nu ahakpɔ wo gbɔ.
03 Welding hot cracks (crystallization cracks le welds, liquefaction cracks le dzoxɔxɔ-affected zone)
Dzoxɔxɔ ƒe gbagbã ƒe seselelãme nɔ te ɖe atike ƒe wɔwɔme, ɖoɖowɔwɔ kple nusi wotsɔ wɔe ƒe dɔwɔwɔ dzi koŋ. NI le bɔbɔe be woawɔ nusiwo me melting point compounds alo eutectic le kple ɖiƒoƒo abe S kple P. Boron kple silicon ƒe vovototodedeameme ana dzoxɔxɔ ƒe ʋuʋu nado ɖe ŋgɔ.
Weld seam la le bɔbɔe be woawɔ coarse conlynar crystal structure si me mɔfiame sẽŋu le, si sɔ na ɖiƒoƒo kple nusiwo gblẽa nu le ame ŋu ƒe vovototodedeameme. Esia doa tsi film si me tsi le si me tsi mele o si yia edzi la wɔwɔ ɖe ŋgɔ eye wònaa dzoxɔxɔ ƒe gbagbã ƒe seselelãme nyona ɖe edzi. Ne dzoxɔxɔ si wotsɔ wɔa xɔa me la mexɔ dzo ɖekae o la, ele bɔbɔe be woawɔ tensile stress si lolo wu eye woado welding hot cracks ƒe dzidzime ɖe ŋgɔ.
Afɔɖeɖe siwo woawɔ atsɔ axe mɔ ɖe enu:
a. Kpɔ ŋusẽ ɖe ɖiƒoƒo siwo gblẽa nu le ame ŋu ƒe nyawo dzi pɛpɛpɛ s kple p.
b. Trɔ asi le weld metal ƒe ɖoɖowɔwɔ ŋu. Dual-phase structure weld la ƒe crack resistance nyo. Delta ƒe akpa si le weld me ateŋu atrɔ asi le nukuawo ŋu, aɖe austenite si ƒe akpa ɖeka ƒe akpa ɖeka ƒe mɔfiame ɖa, aɖe ɖiƒoƒo gbegblẽwo ƒe vovototodedeameme dzi akpɔtɔ le nuku ƒe liƒo dzi, eye delta ƒe akpaa ate ŋu agbã geɖe wu S kple P ate ŋu aɖe ŋusẽ si le wo nɔewo dome dzi akpɔtɔ eye wòawɔ ɖoɖo ɖe tsi si me tsi le dome.
C. Trɔ asi le weld ga alloy ƒe wɔwɔme ŋu. Dzi Mn, C, kple N ƒe agbɔsɔsɔ ɖe edzi nyuie le austenitic gakpo si ƒe akpa ɖeka nye phase me, eye nàtsɔ nu sue aɖewo abe cerium, pickaxe, kple tantalum (si ate ŋu atrɔ asi le weld ƒe wɔwɔme ŋu eye woakɔ nuku ƒe liƒo ŋu), si ate ŋu aɖe dzoxɔxɔ ƒe gbagbã ƒe seselelãme dzi akpɔtɔ.
d. Dɔwɔwɔ ƒe afɔɖeɖewo. Ðe tsita si wotsɔ ƒoe la ƒe dzoxɔxɔ fũ akpa dzi kpɔtɔ be wòaxe mɔ na sɔti siwo le abe sɔti ene siwo le ʋeʋẽm la ƒe wɔwɔme. Zã dzoxɔxɔ sue aɖe kple cross-section weld beads suewo. An . Arc stabilizing device ate ŋu akpe ɖe eŋu le welding me be woaɖe nuto si me woʋuʋu ta la dzi akpɔtɔ, ana dɔwɔwɔ ƒe ŋutete nanyo ɖe edzi le welding tu la me, eye wòana welding ƒe nyonyome nanyo ɖe edzi.
Le kpɔɖeŋu me, austenitic gakpo 25-20 nyea tsi si me tsi le bɔbɔe. Ate ŋu adzɔ be woaɖo seɖoƒe na ɖiƒoƒo ƒe agbɔsɔsɔ kple nuku ƒe lolome si le gɔmeɖoanyinu la ŋu vevie, axɔ ŋusẽ gã ƒe kpekpeme ƒe welding mɔnuwo, dzoxɔxɔ sue aɖe ƒe gege ɖe eme eye woadzi ƒunukpeƒeawo ƒe fafa ƒe agbɔsɔsɔ ɖe edzi.
04 welded joints ƒe embrittlement .
Ele be gakpo si ŋu dzoxɔxɔ le nakpɔ egbɔ be ƒunukpeƒe siwo wotsɔ ga ƒo ƒui la ƒe plasticity be woaxe mɔ ɖe dzoxɔxɔ si nu sẽ nu; Wobia tso gakpo siwo ƒe dzoxɔxɔ mede o si be woƒe sesẽ nyui si me dzoxɔxɔ mele o nanɔ wo ŋu be woaxe mɔ ɖe ƒunukpeƒe siwo wotsɔ ga wɔe ƒe gbagbã si me dzoxɔxɔ mele o nu.
05 gã welding ƒe tɔtɔ .
Le dzoxɔxɔ ƒe tsɔtsɔme si bɔbɔ kple kekeɖenu ƒe xexlẽdzesi gã ta la, welding deformation la lolo, eye woate ŋu azã clamps atsɔ axe mɔ ɖe deformation nu. Austenitic gakpo si mexɔ dzo o ƒe mɔnu si wozãna tsɔ wɔa welding kple welding nuawo tiatia:
Austenitic gakpo si mexɔ dzo o ate ŋu atsɔ argon tungsten arc welding (Tig), molten argon arc welding (mig), plasma argon arc welding (paw) kple tsi si wotsɔ ƒo ƒu (SAW) awɔ.
Austenitic gakpo si mexɔ dzo o la ƒe welding current mesɔ gbɔ o le eƒe ʋeʋẽ si mebɔ o, dzoxɔxɔ ƒe tsɔtsɔme si bɔbɔ, kple elektrikŋusẽ ƒe tsitretsitsi si le ʋeʋẽm ta. Ele be woazã weld kple beads kpuiwo atsɔ aɖe dzoxɔxɔ si nu sẽna ƒe nɔƒe dzi akpɔtɔ, axe mɔ ɖe carbide ƒe tsidzadza nu, aɖe weld shrinkage stress dzi akpɔtɔ, eye wòaɖe dzoxɔxɔ ƒe gbagbã ƒe seselelãme dzi akpɔtɔ.
Nusi wotsɔ wɔa welding-nu, vevietɔ CR kple NI ƒe nusiwo wotsɔ wɔa nusiwo wotsɔ wɔa nu bubuwoe, sɔ gbɔ wu nusiwo wotsɔ wɔa nusiwo wotsɔ wɔa nuawoe tɔ. Zã welding nu siwo me ferrite ƒe agbɔsɔsɔ sue aɖe (4-12%) le be nàkpɔ egbɔ be crack resistance nyui (fafɛ, cracking, stress corrosion cracking) dɔwɔwɔ le weld la me.
Ne womeɖe mɔ ɖe ferrite ƒe akpaa ŋu alo mate ŋu adzɔ le weld me o la, ele be nusi wotsɔ wɔa nu la nanye welding material si me Mo, Mn kple alloy nu bubuwo le.
Ele be C, S, P, Si, kple NB si le welding-nu me la nabɔbɔ alesi woate ŋui. NB ana solidification cracks le austenitic weld dzadzɛa me, gake woate ŋu aƒo asa na ferrite sue aɖe le weld la me nyuie.
Le welding xɔtuɖoɖo siwo wòle be woali ke alo stress-relieved le welding megbe la, zi geɖe la, wozãa nb-siwo me welding nuawo le. Wozãa nyrɔ̃nu si nye nyrɔ̃ ɖe tsi me tsɔ ƒoa titina gbadzɛa nu ƒu, eye woate ŋu atsɔ CR kple NI ƒe dzobibi ƒe bu la akpe ɖe eŋu to flux ƒe tɔtrɔ kple akɔbli ƒe akpa siwo le welding wire la me;
Le gogloƒe gã la ƒe goglome ta la, ele be woakpɔ nyuie be woaxe mɔ ɖe ʋuʋudedi dzodzoe siwo le weld titina kple nusiwo tsi tre ɖe wo nɔewo ŋu dzi ɖeɖe kpɔtɔ le teƒe si dzoxɔxɔ le la nu. Ele be woalé ŋku ɖe welding wire si le tsɛ wu kple welding heat input si le sue wu tiatia ŋu. Ele be welding wire la naɖiɖi le Si, S, kple p.
Mele be ferrite si le gakpo si mexɔ dzo o ƒe dzoxɔxɔ si te ŋu nɔa te ɖe dzoxɔxɔ nu me nawu 5% o. Le austenitic gakpo si mexɔ dzo o si me CR kple NI ƒe agbɔsɔsɔ wu 20% le gome la, ele be woazã MN si kɔkɔ (6-8%) welding wire, eye ele be woazã alkaline alo neutral flux abe flux ene be woatsɔ axe mɔ na SI tsɔtsɔ kpe ɖe weld ŋu eye wòana eƒe crack resistance nanyo ɖe edzi.
Sisi tɔxɛ na austenitic gakpo si mexɔ dzo o la ƒe SI ƒe dzidziɖedzi sue aɖe koe, si ate ŋu atsɔ akɔbli la ayi weld la gbɔ eye wòaxe fe ɖe dzobibi ƒe bublu ƒe akɔbli nuawo be woawɔ ɖe weld ƒe dɔwɔwɔ kple atikewo ƒe wɔwɔme ƒe nudidiwo dzi.
