Engeri y’okuweta (welding characteristics) ey’ekyuma ekitali kizimbulukuse ekya austenitic: okunyigirizibwa n’okunyigirizibwa mu buveera n’okunyigirizibwa mu kiseera ky’okuweta binene nnyo, naye enjatika ennyogovu tezitera kulabibwa. Tewali kitundu kya kuzikira n’empeke ezikaza mu weld, kale amaanyi g’okusika (tensile strength) ga weld gali waggulu nnyo.
Ebizibu ebikulu eby’ekyuma ekitali kizimbulukuse ekya austenitic: okukyukakyuka okunene okw’okuweta; Olw’engeri yaayo ey’ensalosalo z’empeke n’okuwuliziganya ku bucaafu obumu obw’okulondoola (S, P), kyangu okufulumya enjatika ez’ebbugumu.
Ebizibu bitaano ebikulu eby’okuweta n’engeri y’okulongoosaamu ekyuma ekitali kizimbulukuse ekya austenitic .
01 Okutondebwa kwa chromium carbide kukendeeza ku busobozi bwa weld okuziyiza okukulukuta okw’omu bitundu by’omubiri (intergranular corrosion).
Intergranular corrosion: Okusinziira ku ndowooza ya chromium depletion, chromium carbide etonnya ku nsalo z’empeke nga weld ne heat-affected zone zibuguma ku sensitization temperature zone ya 450-850°C, ekivaamu chromium-depleted grain boundaries, nga zino tezizikirira kuziyiza.
(1) Ebipimo bino wammanga bisobola okukozesebwa okukomya okukulukuta wakati w’omusono gwa weld n’okukulukuta mu kitundu ky’ebbugumu ly’okuwuliziganya ku kintu ekigendererwa:
omu. Kendeeza ku kaboni ali mu kyuma ekikulu ne weld, era osseeko elementi ezitebenkeza TI, NB n’ebintu ebirala ku kyuma ekikulu okukulembeza okutondebwa kwa MC okwewala okutondebwa kwa CR23C6.
b. Fuula weld okukola dual-phase structure ya austenite n’akatono aka ferrite. Bwe wabaawo omuwendo ogugere ogwa ferrite mu weld, empeke zisobola okulongoosebwa, ekitundu ky’empeke kisobola okwongerwako, era enkuba ya chromium carbide buli yuniti y’ekitundu ky’ensalo y’empeke esobola okukendeezebwa.
Chromium etabulwa nnyo mu ferrite. CR23C6 esinga kukolebwa mu ferrite awatali kuleeta nsalosalo z’empeke za austenite okuggwaamu mu chromium; Okusaasaana kwa ferrite wakati wa austenites kuyinza okuziyiza okukulukuta okuyita mu nsalosalo y’empeke okutuuka ku kusaasaana okw’omunda.
c. Fuga obudde bw’okubeera mu bbugumu ly’okumanyisa. Adjust the welding thermal cycle, shorten the residence time of 600～1000℃ as much as possible, choose a welding method with high energy density (such as plasma argon arc welding), select a smaller welding heat input, and use argon gas on the back of the weld or use a copper pad Increase the cooling rate of the welded joint, reduce the arc starting and ending times to avoid repeated heating, and the contact surface with the Ekisannyalazo ekivunda mu kiseera ky’okuweta multilayer kisaana okuweta nga bwe kisoboka nga bwe kisoboka.
d. Oluvannyuma lw’okuweta, kola okulongoosa mu solution oba okutebenkeza annealing (850～900°C) n’okunyogoza empewo okufuula carbide charge okufuluma n’okwanguya okusaasaana kwa chromium).
(2) okukulukuta kw’ebiweta mu ngeri y’ekiso. Olw’ensonga eno, bino wammanga bisobola okukolebwa:
Olw’obusobozi obw’amaanyi obw’okusaasaana kwa kaboni, ejja kwawula mu nsalosalo y’empeke okukola embeera ya supersaturated mu kiseera ky’okunyogoza, ate TI ne Nb zisigala mu kirisitaalo olw’obusobozi obutono obw’okusaasaana. Weld bweba ezzeemu okubuguma mu sensitization temperature range, supersaturated carbon ejja kutonnya mu ngeri ya CR23C6 wakati wa crystals.
omu. okukendeeza ku kaboni alimu. Ku kyuma ekitali kizimbulukuse ekirimu elementi ezitebenkeza, kaboni alimu tekirina kusukka 0.06%.
b. Kozesa enkola ensaamusaamu ey’okuweta. Londa ebbugumu ettono ery'okuweta okukendeeza ku budde bw'okubeera mu kitundu ekibuguma ennyo ku bbugumu erya waggulu, era weetegereze okwewala ekikolwa kya 'okumanyisa ebbugumu ery'omu makkati' mu kiseera ky'enkola y'okuweta.
Bwe wabaawo okuweta ku njuyi bbiri, weld mu kukwatagana n’ekintu ekivunda (corrosive medium) erina okuweerezebwa okusembayo (eno y’ensonga lwaki welding ey’omunda eya payipu za welded ennene-diameter obuwanvu zikolebwa oluvannyuma lw’okuweta ebweru). Bwe kiba nga tekisobola kuteekebwa mu nkola, okulaga welding ne weld shape birina okutereezebwa, era gezaako okwewala ekitundu ekibuguma ekisukkiridde okukwatagana n’ekintu ekikosa nate kiwuliziganya era kibuguma.
c. Okulongoosa ebbugumu oluvannyuma lw’okuweesa. Okukola eddagala oba okutebenkeza obujjanjabi oluvannyuma lw’okuweta.
02 Stress corrosion okukutuka .
Ebikolwa bino wammanga bisobola okukozesebwa okuziyiza okubeerawo kw’enjatika z’okukulukuta kw’okunyigirizibwa:
omu. Londa bulungi ebintu era otereeze bulungi ekirungo kya weld. High-purity chromium-nickel austenitic stainless steel, high silicon chromium-nickel austenitic stainless steel, ferritic-austenitic stainless steel, high-chromium ferritic stainless steel, etc. have good stress corrosion resistance, and the weld metal is austenitic It has good stress corrosion resistance in the structure of the dual-phase steel of stenite and ferrite.
b. Ggyawo oba okukendeeza ku situleesi esigaddewo. Kiyinza okukozesebwa mu kulongoosa ebbugumu oluvannyuma lw’okuwunyiriza situleesi, gamba nga A Obukuumi bw’empewo ku layini okulongoosa ebbugumu okuyitirira induction annealing furnace . akwata omusingi gw’okufumbisa okuyingiza. Ekikoomi ekitangaavu eky’okufumba . Hangao Tech (Seko Machinery) tekyetaagisa kusooka kubuguma, etwala sekondi 15 zokka okutuuka amangu ku bbugumu erisinga obulungi ery’okusengejja. Mu kiseera kye kimu, erina okunywezebwa kw’empewo okw’ekika ekya waggulu, ekiyinza okuziyiza obulungi empewo okudda emabega mu kiseera ky’okuzimbulukuka. Payipu ya welded ekoleddwa mu annealed erina ensengekera y’ekyuma ekimu era situleesi ya intergranular n’efuuka entono. Okugatta ku ekyo, enkola z’ebyuma nga okusiimuula, okukuba amasasi mu ssasi n’okukuba ennyondo nazo zisobola okukendeeza ku situleesi esigaddewo ku ngulu.
c. Enzimba ensaamusaamu dizayini. Okwewala okussa essira ku situleesi ennene.
