Ekyuma ekitali kizimbulukuse kisobola okwawulwamu ebika bina okusinziira ku nsengeka y’ekyuma kyakyo, kwe kugamba, ekyuma ekitali kizimbulukuse ekya austenitic, ekyuma ekitali kizimbulukuse ekya ferritic, ekyuma ekitali kizimbulukuse ekya martensitic, n’ekyuma ekitali kizimbulukuse ekya austenitic-ferritic duplex stainless. Wammanga okusinga okwekenneenya engeri y’okuweta (welding characteristics) ey’ekyuma ekitali kizimbulukuse ekya austenitic n’ekyuma ekitali kizimbulukuse eky’amakubo abiri.
(1) Okuweta ekyuma ekitali kizimbulukuse ekya austenitic .
Austenitic stainless steel kyangu okuweta okusinga ebyuma ebirala ebitali bimenyamenya. Tewali nkyukakyuka ya phase ebaawo ku bbugumu lyonna, era tekwatagana na kuzimba kwa haidrojeni. Austenitic stainless steel joints nazo zirina obuveera obusingako n’obugumu mu mbeera ya welded. Ebizibu ebikulu eby’okuweta bye bino: okuweta enjatika ezookya, okunyeenyezebwa, okukulukuta kw’ebitundu ebikulukuta n’okukulukuta kw’okunyigirizibwa. Okugatta ku ekyo, olw’obutambuzi bw’ebbugumu obubi, omugerageranyo gw’okugaziya ogw’ennyiriri omunene, okunyigirizibwa okunene okw’okuweta n’okukyukakyuka. Nga tuweta, ebbugumu eriyingira mu kuweta lirina okuba ettono nga bwe kisoboka, era teririna kusooka kubuguma, era ebbugumu ery’omu kisenge (interlayer temperature) lirina okukendeezebwa. Ebbugumu erya wakati lirina okufugibwa wansi wa 60°C, era ebiyungo bya weld birina okutabuka. Okukendeeza ku bbugumu eriyingira, sipiidi y’okuweta tesaana kwongerwako nnyo, wabula erina okukyusibwa okukendeeza ku kasannyalazo k’okuweta.
(2) Okuweta kwa austenitic-ferritic two-phase stainless steel .
Austenitic-ferritic bidirectional ekyuma ekitali kizimbulukuse kye kyuma ekitali kizimbulukuse duplex ekikolebwa austenite ne ferrite. Egatta ebirungi ebiri mu kyuma kya austenitic ne ferritic steel, kale erina engeri z’amaanyi amangi, okuziyiza okukulukuta okulungi n’okuweta okwangu. Mu kiseera kino, okusinga waliwo ebika bisatu eby’ebyuma ebitali bimenyamenya ebiyitibwa duplex: CR18, CR21, ne CR25. Ebikulu ebiraga ekika ky’ekyuma kino welding bye bino: bw’ogeraageranya n’ekyuma ekitali kizimbulukuse ekya austenitic, kirina thermal tendency eya wansi; Bw’ogeraageranya n’ekyuma ekitali kizimbulukuse ekya pure ferritic, erina omuze omutono ogw’okukutuka oluvannyuma lw’okuweta, era ddiguli ya ferrite coarsening mu zone ekoseddwa ebbugumu mu welding nayo eri wansi, kale weldability esinga.
Olw’omutindo omulungi ogw’okuweta ogw’ekika kino, okusooka okubuguma n’okubuguma tebyetaagisa mu kiseera ky’okuweta. Puleti ennyimpi zirina okuweweeza TIG, era obubaawo obwa wakati n’obuwanvu busobola okuweta ne electrode arc welding. Electrode ey’enjawulo erimu ekirungo ekifaanagana n’ekyuma ekikulu oba austenitic electrode nga erimu kaboni omutono erina okulondebwa okuweta kwa electrode arc. Electrodes ezikolebwa mu nickel nazo zisobola okukozesebwa ku kyuma kya CR25 dual-phase.
Due to the existence of a large proportion of ferrite in dual-phase steels, the inherent embrittlement tendency of ferritic steels, such as brittleness at 475°C, σ phase precipitation embrittlement and coarse grains, still exist because of the presence of austenite The balance effect of the welding machine can be relieved to a certain extent, so you still need to pay attention to it when welding. Bwe kiba nga kiweta ebyuma ebitali bimenyamenya ebiyitibwa duplex nga tebirina NI oba NI wansi, waliwo omuze gw’okunyweza ferte n’empeke mu kitundu ekikoseddwa ebbugumu. Mu kiseera kino, okufaayo kulina okussibwako okufuga ebbugumu eriyingira mu welding, n’okugezaako okukozesa akasannyalazo akatono, sipiidi ya welding eya waggulu, n’okuweta okuyita mu kuyita. ne multi-pass welding okuziyiza empeke coarsening ne single-phase ferrite mu heat-affected zone, ebbugumu wakati wa layers terina kuba waggulu nnyo, era kirungi weld okuweta ekiddako pass oluvannyuma lw’okunnyogoga.
Ebyo byombi waggulu bika ebyangu okuweta. Wabula waliwo n’ebika by’ebyuma ebitali bimenyamenya nga tebirina weldability embi, nga ferrite. Mu kiseera kino, tukukubiriza okulowooza ku kikozesebwa kyaffe eky’okuweta eky’okuweta-Electromagnetic control arc okutebenkeza .. Hangao Tech (Seko Machinery) yafunza obumanyirivu n’ebikwata ku by’okukola ebyuma ebikozesebwa mu kukola payipu eziweerezeddwa mu myaka 20 egiyise, bwe kityo wadde nga sipiidi y’okuweta erongooseddwa, esobola n’okulowooza ku mutindo gwa weld. Omutindo gwa weld gukakasiddwa, era payipu eya welded bw’eyingira mu nkola eddako ey’okukola, omuwendo gw’ebisasiro guyinza okukendeezebwa obulungi era ebifulumizibwa bisobola okwongerwako.
