1. Selelekela

ASTM A333 Gr.6ke thepa ea phaephe ea tšepe ea carbon e sebelisoang haholo mochesong o tlase, e nang le mocheso o tlase oa tšebeletso oa -45°C. Ka lebaka la ho tiea ha eona ho phahameng mochesong o tlase le katleho ea litšenyehelo, e sebelisoa haholo lifemeng tsa petrochemical, lisebelisoa tsa cryogenic, le litsamaisong tsa phetisetso ea khase e metsi.

Ho rekeng thepa ea boenjiniere,Liphaephe tsa A333 Gr.6Hangata di arolwa ka maemo a mabedi a phepelo: "Tshebeletso e Bolila" le "Tshebeletso e Monate" (e tloaelehileng/e tlwaelehileng). Leha mefuta ena ka bobedi e fihlela ditlhoko tsa motheo tsa sebopeho sa dikhemikhale le thepa ya mechini ya tekanyetso ya ASTM A333, di fapana ka ho feletseng kganyetsong ya tsona ho corrosion ya hydrogen sulfide (H₂S)—phapang e etsang hore maemo a tsona a tshebediso a fapane ka ho hlaka.

2. Phapang ea Bohlokoa Pakeng tsa Tšebeletso e Bolila le e Monate

2.1 Maemo a Tšebeletso

Tšebeletso e Monate (Ha e na bolila): E loketse libaka tse se nang H₂S kapa tse nang le khatello e fokolang ea H₂S e tlase haholo. Lintho tsa mantlha tse lokelang ho nahanoa ka moralo ke ho tiea ha mocheso o tlase le bokhoni ba setso ba ho jara khatello.

Tšebeletso e Bolila: E etselitsoe ka ho khetheha libaka tse nang le H₂S e metsi, moo thepa e lokelang ho mamella mocheso o tlase le ho bola ha H₂S ka nako e le 'ngoe. Lisebelisoa tsa tšebeletso e bolila le tsona lia amoheleha ka botlalo bakeng sa lits'ebetso tsa tšebeletso e monate.

2.2 Taolo ea Sebopeho sa Lik'hemik'hale

Leha tlhaloso ea motheo ea ASTM A333 Gr.6 e beha meeli bakeng sa C, Mn, P, S, le likarolo tse ling, liphaephe tsa tšebeletso ea sour li hloka taolo e matla haholo ea lik'hemik'hale:

Paramethara	A333 Gr.6 e Tloaelehileng	Tšebeletso e Bolila A333 Gr.6
Sebabole (S)	≤ 0.035%	E laoloa ka thata, hangata ≤ 0.015%
Fosforase (P)	≤ 0.035%	E laoloa ka thata, hangata ≤ 0.025%
Tekanyo ea Khabone (CE)	Ha se tlamo	E lekanyelitsoe haholo (mohlala, ≤ 0.43%) ho thibela ho thatafala ho feteletseng

Ka ho fokotsa litšila tse kang S le P, le ho fokotsa se lekanang le khabone, liphaephe tsa tšebeletso ea sour li fokotsa ho pepesehela ho petsoha ha sulfide stress corrosion (SSC) ho latela pono ea metsoako ea lik'hemik'hale.

2.3 Litlhoko tsa ho tiea le ho phekola mocheso

Taolo ea ho thatafala ke e 'ngoe ea liphapang tsa bohlokoa ka ho fetisisa pakeng tsa tšebeletso e bolila le e monate. Tšebeletso e bolila A333 Gr.6 e hloka ho thatafala ho hoholo ha 22 HRC (Rockwell C) kapa 248 HBW. Sena se bakoa ke hore meaho e menyenyane ea ho thatafala ho hoholo e na le tšekamelo e kholo ea ho qhibilihisoa ke haeterojene le ho petsoha ha mafome a khatello tikolohong ea H₂S.

Mabapi le kalafo ea mocheso, liphaephe tsa tšebeletso ea sour hangata li hloka lits'ebetso tse tloaelehileng kapa tse phehiloeng le tse tenyetsehang (Q&T) ho fihlela sebopeho se senyenyane se ts'oanang, se nang le sebopeho se setle se eketsang khanyetso ea SSC. Liphaephe tsa tšebeletso tse tloaelehileng (tse monate) li na le litlhoko tse phutholohileng tsa kalafo ea mocheso.

2.4 Litlhoko tse ling tsa Teko

Liphaephe tsa tšebeletso ea sour li tlameha ho netefatsoa ho latela melao ea NACE (mohlala, NACE MR0175 / ISO 15156), hangata ho kenyeletsoa:

Teko ea SSC (Sulfide Stress Cracking, NACE TM0177)

Teko ea HIC (Ho Petsoha ho Bakiloeng ke Haedrojene, NACE TM0284)

Liphaephe tsa tšebeletso tse tloaelehileng (tse monate) ka kakaretso li hloka feela ho fihlela litlhoko tsa teko ea tšusumetso ea mocheso o tlase oa ASTM A333 (-46°C, bonyane matla a tšusumetso a karolelano ≥ 20J) hammoho le netefatso ea thepa ea mechini e tloaelehileng.

3. Kakaretso le Litlhahiso tsa Khetho

Karolo	A333 Gr.6 e Tloaelehileng	Tšebeletso e Bolila A333 Gr.6
Mokhoa oa Tšebeletso	Ha ho H₂S kapa H₂S e sa reng letho	Metsi a nang le H₂S a bolila
Moeli oa ho tiea	Ha ho thibelo e khethehileng	≤ 22 HRC / 248 HBW
Kalafo ea Mocheso	Ts'ebetso e tloaelehileng	Sebopeho se tloaelehileng kapa sa Q&T; se tšoanang
Teko e Eketsehileng	Teko ea tšusumetso ea mocheso o tlase	Teko ea SSC + HIC ho latela maemo a NACE
Ho Latela Melao ea NACE	Ha ho hlokahale	Ho latela melao ea NACE MR0175

Litlhahiso tsa Khetho: Nakong ea mohato oa moralo, ho bohlokoa ho fumana hore na H₂S e teng tikolohong ea litšebeletso. Haeba maemo a H₂S a metsi a le teng, tlhaloso ea theko e tlameha ho bolela ka ho hlaka "A333 Gr.6 bakeng sa Tšebeletso e Bolila, e lumellanang le NACE MR0175 / ISO 15156," ka litlhoko tse hlakileng tsa ho thatafala, ho lekana le khabone, kalafo ea mocheso, le liteko tse ling. Liphaephe tse tloaelehileng tsa A333 Gr.6 ha lia lokela ho sebelisoa mecheng ea bolila, kaha sena se ka lebisa ho hloleheng ho hoholo ha khatello ea khatello ea mafome.