1. Chiyambi

ASTM A333 Gr.6ndi chitoliro cha chitsulo cha kaboni chomwe chimagwiritsidwa ntchito kwambiri chomwe chimagwiritsidwa ntchito kutentha pang'ono, ndipo kutentha kwake kocheperako ndi -45°C. Chifukwa cha kulimba kwake kotsika kutentha komanso kugwiritsa ntchito bwino ndalama, chimagwiritsidwa ntchito kwambiri m'mafakitale a petrochemical, zida za cryogenic, ndi makina otumizira mpweya wamadzimadzi.

Mu kugula zinthu zaukadaulo,Mapaipi a A333 Gr.6Nthawi zambiri amagawidwa m'magulu awiri: "Sour Service" ndi "Sweet Service" (yachizolowezi/yachizolowezi). Ngakhale kuti mitundu yonse iwiri imakwaniritsa zofunikira za kapangidwe ka mankhwala ndi kapangidwe ka makina a muyezo wa ASTM A333, imasiyana kwambiri pakukana kwawo ku hydrogen sulfide (H₂S) corrosion—kusiyana komwe kumatsimikizira momwe amagwiritsidwira ntchito mosiyana.

2. Kusiyana Kwakukulu Pakati pa Utumiki Wowawasa ndi Wotsekemera

2.1 Mikhalidwe ya Utumiki

Utumiki Wokoma (Wosawawa): Woyenera malo opanda H₂S kapena okhala ndi kupanikizika pang'ono kwa H₂S kochepa kwambiri. Zofunika kwambiri pakupanga ndi kulimba kwa kutentha kochepa komanso mphamvu yachizolowezi yonyamula kupanikizika.

Utumiki Wopanda Mphamvu: Wopangidwira makamaka malo okhala ndi H₂S yonyowa, komwe zinthuzo ziyenera kupirira kutentha kochepa komanso dzimbiri la H₂S nthawi imodzi. Zipangizo zogwirira ntchito zopanda mphamvu ndizovomerezeka mokwanira kuti zigwiritsidwe ntchito potumikira zotsekemera.

2.2 Kulamulira Kapangidwe ka Mankhwala

Ngakhale kuti mfundo za ASTM A333 Gr.6 zoyambira zimaika malire a C, Mn, P, S, ndi zinthu zina, mapaipi operekera sour amafunika kulamulira mankhwala mwamphamvu kwambiri:

Chizindikiro	Muyezo A333 Gr.6	Utumiki Wowawasa A333 Gr.6
Sulfure (S)	≤ 0.035%	Yolamulidwa mwamphamvu, nthawi zambiri ≤ 0.015%
Phosphorus (P)	≤ 0.035%	Yolamulidwa mwamphamvu, nthawi zambiri ≤ 0.025%
Chofanana ndi Kaboni (CE)	Sikofunikira	Zochepa kwambiri (monga, ≤ 0.43%) kuti tipewe kuuma kwambiri

Mwa kuchepetsanso zinyalala monga S ndi P, ndikuchepetsa kaboni wofanana, mapaipi operekera sour amachepetsa kuopsa kwa sulfide stress corrosion cracking (SSC) kuchokera ku kapangidwe ka mankhwala.

2.3 Zofunikira pa Kuuma ndi Kutentha

Kulamulira kuuma ndi chimodzi mwa zinthu zofunika kwambiri zomwe zimasiyanitsa pakati pa ntchito yowawasa ndi yotsekemera. Ntchito yowawasa A333 Gr.6 imafuna kuuma kwakukulu kwa 22 HRC (Rockwell C) kapena 248 HBW. Izi zili choncho chifukwa chakuti zinthu zazing'ono zolimba kwambiri zimakhala ndi vuto la kuphulika kwa haidrojeni komanso kusweka kwa dzimbiri m'malo a H₂S.

Ponena za kuchiza kutentha, mapaipi oyeretsera sour nthawi zambiri amafunikira njira zokhazikika kapena zozimitsidwa ndi zotenthetsera (Q&T) kuti akwaniritse kapangidwe kake kofanana, kosalala komwe kumawonjezera kukana kwa SSC. Mapaipi oyeretsera okhazikika (okoma) ali ndi zofunikira zochepa pakuchiza kutentha.

2.4 Zofunikira Zowonjezera pa Mayeso

Mapaipi a sour service ayenera kutsimikiziridwa kuti akutsatira miyezo ya NACE (monga, NACE MR0175 / ISO 15156), nthawi zambiri kuphatikizapo:

Kuyesa kwa SSC (Kuphwanya Kupsinjika kwa Sulfide, NACE TM0177)

Kuyesa kwa HIC (Kuphwanya Koyambitsidwa ndi Hydrogen, NACE TM0284)

Mapaipi ogwiritsidwa ntchito wamba (okoma) nthawi zambiri amangofunika kukwaniritsa zofunikira zoyesera kutentha kochepa za ASTM A333 (-46°C, mphamvu yocheperako yapakati ya mphamvu ≥ 20J) pamodzi ndi kutsimikizira kwanthawi zonse kwa katundu wamakina.

3. Chidule ndi Malangizo Osankha

Mbali	Muyezo A333 Gr.6	Utumiki Wowawasa A333 Gr.6
Utumiki Wapakati	Palibe H₂S kapena H₂S yocheperako	Chonyowa chokhala ndi H₂S
Malire Olimba	Palibe choletsa chapadera	≤ 22 HRC / 248 HBW
Kutentha Chithandizo	Kukonza kwachizolowezi	Kapangidwe ka microstructure kofanana kapena Q&T
Kuyesa Kowonjezera	Mayeso a kutentha kochepa	Kuyesa kwa SSC + HIC motsatira miyezo ya NACE
Kutsatira Malamulo a NACE	Sikofunikira	Kutsatira malamulo a NACE MR0175

Malangizo Osankha: Pakapangidwe kake, ndikofunikira kudziwa ngati H₂S ilipo pamalo ogwirira ntchito. Ngati pali mikhalidwe yonyowa ya H₂S, mfundo yogulira iyenera kunena momveka bwino kuti "A333 Gr.6 ya Sour Service, yogwirizana ndi NACE MR0175 / ISO 15156," yokhala ndi zofunikira zomveka bwino pakulimba, kufanana ndi kaboni, chithandizo cha kutentha, ndi mayeso owonjezera. Mapaipi a Standard A333 Gr.6 sayenera kugwiritsidwa ntchito m'malo onyowa, chifukwa izi zingayambitse kuwonongeka kwakukulu kwa dzimbiri.