Situleesi ey’omunda egenda mu maaso oluvannyuma lw’okumaliriza okuweta n’okunyogoza okujjuvu eyitibwa welding residual stress. Welding Residual Stresses ziteekebwa mu kibinja kino wammanga:
1. Okusinziira ku kivaako situleesi .
(1) Okunyigirizibwa okw’ebbugumu: Okuweta nkola ya kubugumya n’okunyogoza obutafaanagana. Situleesi munda mu weldment esinga kuva ku njawulo y’ebbugumu n’ebbugumu etali ya bwenkanya, eyitibwa thermal stress, era emanyiddwa nga temperature stress.
(2) Okuziyiza okunyigirizibwa: okunyigirizibwa okusinga okuva ku nsengekera yennyini oba okuziyiza okw’ebweru kuyitibwa situleesi y’okuziyiza.
(3) Okunyigirizibwa kw’enkyukakyuka ya phase: okunyigirizibwa okusinga okuva ku nkyukakyuka y’ensengekera y’obutonde obutakwatagana mu kitundu ky’ekiyungo ekiweereddwa welded kiyitibwa phase transformation stress, era ekimanyiddwa nga microstructure stress.
(4) Stress evudde ku haidrojeni: okunyigirizibwa okusinga okuva mu kukuŋŋaanyizibwa kwa haidrojeni okusaasaana ku buzibu obutonotono (microscopic defects).
Mu bizibu bino ebina ebisigaddewo, okunyigirizibwa kw’ebbugumu kwe kusinga. N’olwekyo, okusinziira ku bivaako situleesi, esobola okwawulwamu ebika bibiri: okunyigirizibwa okw’ebbugumu (okunyigirizibwa okw’ebbugumu) n’okunyigirizibwa kw’enkyukakyuka ya phase (okunyigirizibwa kw’ebitundu).
2. Okusinziira ku ndagiriro ya situleesi mu bwengula .
Kiyinza okwawulwamu situleesi y’engeri emu, situleesi y’engeri bbiri n’okunyigirizibwa mu ngeri ssatu .
(1) Okunyigirizibwa okw’oludda olumu: okunyigirizibwa okuliwo mu ludda olumu mu weldment kuyitibwa okunyigirizibwa okw’oludda olumu, era okumanyiddwa nga okunyigirizibwa kwa layini. Okugeza, welds z’akabina eza welded sheets ne stress ezikolebwa nga zifuluma kungulu ku weldment.
(2) Okunyigirizibwa okw’enjuyi ebbiri: okunyigirizibwa okukola ku ndagiriro bbiri ezikwatagana mu nnyonyi y’okuweta eyitibwa bidirectional stress, era emanyiddwa nga okunyigirizibwa kw’ennyonyi. Kitera okubaawo mu bizimbe ebiweereddwa (welded structures) eby’ebipande ebya wakati n’ebizito nga biriko obuwanvu bwa mm 15-20.
(3) Situleesi ey’engeri ssatu: Situleesi ekola mu njuyi ssatu nga yeesimbye ku ndala mu weldment eyitibwa three-way stress, era emanyiddwa nga volume stress. Okugeza, situleesi ku nkulungo ya butt weld ya welded thick plate ne welds mu njuyi ssatu nga zeesimbye ku ndala.
Okugaziwa kw’obunene n’okukonziba kw’ekyuma bwe kibuguma ne kinyogoza biba mu njuyi ssatu, kale mu ngeri enkakali, okunyigirizibwa okusigaddewo okukolebwa mu weldment bulijjo kuba kwa maanyi ga ngeri ssatu. Naye omuwendo gw’okunyigirizibwa mu ndagiriro emu oba bbiri bwe guba mutono nnyo era nga guyinza okubuusibwa amaaso, guyinza okutwalibwa ng’okunyigirizibwa okw’oludda olubiri oba okunyigirizibwa okw’oludda olumu, era waggulu ye mbeera y’ekika ky’okunyigirizibwa okusigaddewo okw’okuweta.
Mu nkola y’okufulumya payipu eziweereddwa, ekyuma kya strip kyetaaga okufulumizibwa, okufukamira, okutondebwa n’okuweebwa weld. Mazima ddala wajja kubaawo situleesi mu kiseera ekyo. Okusobola okufuna payipu eziweereddwa mu makolero nga zirina omulimu ogw’oku ntikko, situleesi zino zirina okuggyibwawo. Mu kiseera kye kimu, nga tutunuulidde okunyigirizibwa kw’omuwendo gw’ensimbi mu bbanga eggwanvu, kyetaagisa okufuna engeri ennungi era ekekkereza amaanyi. Hangao Tech (Ebyuma bya Seko) Single-tube energy-saving bright annealing induction heater ekyuma tekisobola kuggyawo stress ekolebwa mu kiseera ky’okukola welded tubes, naye era erina eby’okulabirako by’okukekkereza amaanyi n’okukuuma obutonde. Bw’ogeraageranya n’ebintu ebifaanagana, enkozesa ennungi ey’amaanyi eri waggulu ebitundu 20%-30%. Enkola y’okutambula kw’amazzi aganyogoza esobola okutegeera okuddamu okukola eby’obugagga by’amazzi n’okufuga obulungi ssente ezisaasaanyizibwa mu bbanga eggwanvu.
