Hangao Tech (Seko mfiri), a ɛwɔ mfe 20 osuahu wɔ nkɔso ne ne yɛ mu . Stainless steel industrial welded pipe production line equipment , ɛbɛfa wo sɛ wobɛte tebea ahorow a ɛwɔ welding beae a ɔhyew ayɛ no mu wɔ bere a wɔreyɛ welding no ase ne nkɛntɛnso a ɛwɔ weld no su so.
Welding no beae a ɔhyew ka ho (Haz) no yɛ soronko wɔ weld no ho. Wobetumi asiesie welding seams, asan akyekyɛ na wɔayɛ welding a ɛfata denam nnuru a ɛwɔ dade a ɛwɔ ase no mu sɛnea ɛbɛyɛ a wɔbɛhwɛ ma wɔayɛ adwuma no ho ahwehwɛde ahorow no. Nanso, ɛrentumi nyɛ yiye sɛ wɔbɛsesa beae a ɔhyew no aka no no adwumayɛ denam nnuru a ɛwɔ mu so. Ɛyɛ ɔhaw a ɛfa ntini a wɔkyekyɛ no pɛpɛɛpɛ ho a ɛba wɔ ɔhyew a ɛkyinkyini no dwumadi ase nkutoo. Wɔ general welded structures ho no, wosusuw nsɛm anan a ɛfa embrittlement, toughening, hardening, ne softening a ɛwɔ beae a ɔhyew no aka no ho titiriw, ne mfiridwuma mu ahoɔden a ɛkɔ akyiri, ɔbrɛ su, ne corrosion resistance. Ɛsɛ sɛ wosi eyi ho gyinae sɛnea ahwehwɛde pɔtee a ɛwɔ welded nhyehyɛe no mu no te.
1. Welding a ɛyɛ den a ɛwɔ beae a ɛhɔ yɛ hyew no yɛ den .
Sɛnea welding no yɛ den no gyina nnuru a ɛwɔ mu ne onwini tebea a ɛwɔ base material a ɛsɛ sɛ wɔde weld no so titiriw. Nea ɛho hia ne sɛ ɛbɛda nneɛma a ɛwɔ dade ahorow a ɛwɔ dade ahorow mu no su adi. Hardness sɔhwɛ no yɛ nea ɛfata kɛse. Enti, wɔde HMAX a ɛyɛ den a ɛkorɔn sen biara a ɛwɔ beae a ɔhyew a ɛtaa de ba no (mpɛn pii no wɔ fusion zone) no di dwuma de bu beae a ɔhyew no aka no adwumayɛ ho atɛn. Wobetumi de adi dwuma de ahyɛ nkɔm wɔ ɔkwan a ɛnteɛ so sɛ beae a ɔhyew no aka no no yɛ den, ɛyɛ mmerɛw na ɛpaapae. Wɔ nnansa yi mfe mu no, wɔabu HMAX a ɛwɔ HAZ no sɛ ɛyɛ agyiraehyɛde a ɛho hia a wɔde susuw weldability ho. Ɛsɛ sɛ yɛkyerɛ sɛ wɔ ahyehyɛde koro mu mpo no, nneɛma a ɛyɛ den ahorow wɔ hɔ. Eyi ne carbon a ɛwɔ dade a ɛwɔ ase, aduru a wɔde yɛ aduru ne tebea a ɛma onwini mu no wɔ abusuabɔ kɛse. Enti, wɔkamfo kyerɛ sɛ wɔmfa dade a ɛyɛ nea wotumi de ho to so na ɛyɛ daa a wɔyɛ no nni dwuma mma welding na ama wɔahwɛ ahu sɛ ɛyɛ papa.
2. Embrittlement a ɛwɔ welding ɔhyew a ɛka no beae .
Mpɛn pii no, beae a welding no ayɛ hyew no a ɛyɛ mmerɛw no bɛyɛ ade titiriw a ɛma nkwaa a wɔde weld ayɛ no di nkogu na ɛyɛ mmerɛw. Sɛnea mprempren nneɛma a wɔyɛ ho nsɛm ne nsɛm kyerɛ no, nea ɛka ho no bi ne ahwehwɛ a ɛyɛ mmerɛw, osutɔ a ɛyɛ mmerɛw, ɔhyew mu nhyɛso a ɛma ɛyɛ mmerɛw, hydrogen embrittlement, nhyehyɛe mu nsakrae a ɛyɛ mmerɛw, ne graphite a ɛyɛ mmerɛw.
1) Ahwehwɛ a ɛyɛ mmerɛw a ɛyɛ mmerɛw. Esiane nkɛntɛnso a ɔhyew kyinhyia nti, aburow a ɛyɛ mmerɛw no ba wɔ baabi a ɛbɛn fusion line ne beae a ɛyɛ hyew dodo wɔ welded joint no mu. Nnua a ɛyɛ mmerɛw no bɛka sɛnea dade a ɛwɔ ase no yɛ brittleness no kɛse. Sɛ yɛbɛka no mpɛn pii a, dodow a aburow no kɛse yɛ kɛse no, dodow no ara na ɔhyew a ɛyɛ mmerɛw no yɛ kɛse.
2) osutɔ ne embttlement. Wɔ onyin anaa tempering nhyehyɛe no mu no, carbides, nitrides, intermetallic compounds ne metastable intermediates afoforo bɛtɔ wɔ supersaturated solid solution no mu. Saa fã foforo a ɛba ntɛmntɛm yi ma dade anaa aduru a wɔde afra no ahoɔden, ɛyɛ den ne nea ɛyɛ mmerɛw no yɛ kɛse. Wɔfrɛ saa adeyɛ yi sɛ precipitation embrittlement.
3) Ntini mu ntini a ɛyɛ mmerɛw. Wɔfrɛ embrittlement a ɛnam brittle ne hard structure a ɛda adi wɔ welding haz no so no sɛ structure embrittlement. Wɔ dade a ahoɔden a ɛwɔ mu a ɛnyɛ den pii a wɔtaa de di dwuma no fam no, HAZ a wɔde weld ayɛ no nhyehyɛe no fi MA fã, Upper Bainite, ne Widmanstatten nhyehyɛe a ɛyɛ mmerɛw no titiriw. Nanso wɔ dadeɛ a carbon a ɛwɔ mu no dɔɔso (mpɛn pii no ≥0.2%) fam no, nhyehyɛeɛ a ɛyɛ embttlement no firi carbon martensite a ɛwɔ carbon kɛseɛ no titire.
4) thermal strain aging embrittlement a ɛwɔ haz no mu. Ɛsɛ sɛ wɔyɛ welding structure no ho adwuma wɔ manufacturing nhyehyɛe no mu, te sɛ nneɛma, shearing, cold forming, gas cutting, welding ne ɔhyew a wɔde yɛ nneɛma foforo. Mpɔtam hɔ nhyɛso ne plastic deformation a saa dwumadie yi de ba no nya nkɛntɛnsoɔ kɛseɛ wɔ HAZ a wɔde weld no ayɛ no so. Wɔfrɛ embrittlement a saa processing steps yi de ba no sɛ thermal strain aging embrittlement. Strain Aging Embrittlement betumi akyekyɛ mu ayɛ no static strain aging embrittlement ne dynamic strain aging embrittlement. Sɛ yɛbɛka no ɔkwan biara so a, 'blue brittleness' no yɛ adeyɛ a ɛne sɛ ɛyɛ dynamic strain aging.
3. Toughening of welding heat a ɛka ho beae .
Welding haz yɛ nipadua a ɛnyɛ pɛ wɔ nhyehyɛe ne adwumayɛ mu. Fusion zone ne coarse-grained zone titiriw no yɛ nea ɛyɛ mmerɛw sɛ ɛbɛhyɛ mu na ɛyɛ beae a ɛyɛ mmerɛw wɔ welded joint no nyinaa mu. Enti, ɛho hia sɛ wɔma haz a wɔde weld no yɛ den no tu mpɔn. Sɛnea nhwehwɛmu kyerɛ no, wobetumi de akwan abien a edidi so yi adi dwuma de ayɛ HAZ no den.
1) Di ahyehyɛde no so. Ɛsɛ sɛ dade a ɛnyɛ den pii na ɛhwɛ carbon a ɛwɔ mu no so, sɛnea ɛbɛyɛ a alloying element nhyehyɛe no yɛ nhyehyɛe a ɛhyɛ den a ɛwɔ carbon a ɛba fam a ɛyɛ nneɛma pii a wɔde afra mu. Nea ɛde ba ne sɛ, wɔ welding a ɛma onwini no mu no, wɔde nneɛma nketenkete a wɔahyɛ no den a wɔde petepete HAZ no kyekyɛ, na wɔde bainite ne acicular ferrite a ɛwɔ carbon a ɛba fam no ba wɔ ne nhyehyɛe mu a ɛyɛ den yiye. Nea ɛto so abien no, ɛsɛ sɛ wodi aburow ahye mu mpaapaemu so sɛnea wobetumi.
2) Toughening ayaresa. Nneɛma bi a ɛho hia a wɔyɛ no taa de ɔhyew a wɔde ma wɔ WELD akyi di dwuma de ma nkwaa no yɛ adwuma yiye. Nanso, nneɛma akɛse bi a ɛyɛ den a wɔde yɛ adwuma no fa ɔhyew a wɔde yɛ adwuma wɔ mpɔtam hɔ, a ɛyɛ den kɛse wɔ adwumayɛ ankasa mu. Enti, welding heat input a wɔpaw no yiye, welding nhyehyɛe a ntease wom a wɔyɛ, ne nsakrae a wɔyɛ wɔ preheating ne post-heating temperatures mu no yɛ gyinaesi ahorow a etu mpɔn a wɔde bɛma welding no ayɛ den.
Nea ɛka ho no, akwan foforo wɔ hɔ a wɔfa so ma HAZ no mu yɛ den. Sɛ nhwɛso no, dade a ɛyɛ fɛ no fa ɔkwan a wɔahyɛ so so de siesie ferrite aburow no bio, na ɛno nso bɛma nneɛma no ayɛ den. Eyi gyina element a ɛwɔ dade a ɛwɔ ase no ankasa mu na ɛne mfiridwuma a wɔde yɛ nneɛma a wɔde yɛ nneɛma no wɔ abusuabɔ.
Nea ɛto so anan, beae a welding no ayɛ mmerɛw no yɛ mmerɛw .
Wɔ dadeɛ anaa alloys a wɔahyɛ no den denam awɔw mu adwuma a ɛyɛ den anaa ɔhyew a wɔde yɛ adwuma so ansa na welding ayɛ no, mpɛn pii no, mmoawa a wɔde nyarewa ba no ahoɔden dodow bɛkɔ so wɔ welding beae a ɔhyew no aka no. Nea ɛyɛ nea ɛtaa ba ne dade a ahoɔden wom a wɔayɛ no foforo ne aduru a wɔde afra a ɛhyɛ osutɔ mu den ne apete ahoɔden, ne ahoɔden a ɛyɛ mmerɛw anaasɛ ɛyɛ mmerɛw a ɛba wɔ beae a ɔhyew no aka no bere a wɔayɛ welding awie no. Bere a welding dum dade na ɛyɛ tempered no, haz a ɛyɛ mmerɛw no ne ɔhyew ayaresa tebea a ɛwɔ base material no mu no wɔ abusuabɔ ansa na welding. Dodow a ɔhyew a ɛwɔ ɔhyew a wɔde dum ne ɔhyew a wɔde yɛ no mu ba fam ansa na wɔde dade a ɛwɔ ase no ayɛ welding no, dodow no ara na ɛyɛ den sɛ ɛbɛhyɛ no den, na sɛ welding akyi a ɛyɛ mmerɛw no mu yɛ den kɛse. Nhwehwɛmu data dodow bi a mfaso wɔ so kyerɛ sɛ sɛ wɔde welding akwan horow ne welding wire ahoɔden ahorow di dwuma a, gyinabea a ɛda adi kɛse sɛ ɛyɛ mmerɛw wɔ HAZ no mu ne ɔhyew a ɛwɔ A1-A3 ntam.
