ʻO kēia kahi e hui ai kahi pūʻulu kila ma mua o hoʻokahi kikoʻī a i ʻole ka pae. He ala ia e ʻae ai i nā hale kūʻai hoʻoheheʻe e hana ʻoi aku ka maikaʻi o ke kila kila ma ke kaohi ʻana i ka helu o nā ʻano kila like ʻole. Hiki i ka hui kemika a me nā waiwai mechanical o ke kila ke hui aku ma mua o hoʻokahi papa i loko o ka maʻamau hoʻokahi a i ʻole ma kahi o nā kūlana. ʻAe kēia i nā mea kūʻai aku e hōʻemi i nā pae waiwai.

No ka laʻana, he mea maʻamau no 1.4401 a me 1.4404 (316 a me 316L) i ʻelua hōʻoia - ʻo ia ka liʻiliʻi o ke kalapona ma mua o 0.030%. He mea maʻamau nō hoʻi ke kila i hōʻoia ʻia i nā kūlana ʻEulopa a me US.

Nui nā ʻano like ʻole o ka hoʻopau ʻili ma ke kila kila. No ka wili kekahi o ia mau mea akā ua hoʻohana ʻia ka nui ma hope i ka wā e hana ai, no ka laʻana i hoʻoliʻi ʻia, palaki ʻia, pahū, etched a me nā kala kala.

ʻAʻole hiki ke hoʻohālikelike ʻia ke koʻikoʻi o ka hoʻopau ʻana i ka ʻili i ka hoʻoholo ʻana i ke kūpaʻa corrosion o ka ʻili kila kuhili. Hiki ke hoʻohaʻahaʻa maikaʻi i ka pale ʻana i ka corrosion i ka pae haʻahaʻa o ke kila kila.

Hoʻohana ʻia nā ʻano like ʻole o ke kila kila ma waena o ka pae wela holoʻokoʻa mai ka ambient a 1100 deg C. ʻO ke koho ʻana o ka papa ma muli o nā kumu he nui:

ʻO ka wela kiʻekiʻe o ka hana
ʻO ka manawa i ka mahana, ke ʻano cyclic o ke kaʻina hana
ʻAno o ka lewa, oxidizing, hoʻemi, sulphidising, carburising.
Pono ikaika

Ma nā kūlana ʻEulopa, ua hoʻokaʻawale ʻia ma waena o nā kila kila a me nā kila pale wela. Eia nō naʻe, paʻakikī pinepine kēia ʻokoʻa a he mea pono e noʻonoʻo iā lākou he ʻano kila hoʻokahi.

ʻO ka hoʻonui ʻana i ka nui o Chromium a me ke silika e hāʻawi i ka pale ʻana i ka oxidation. ʻO ka hoʻonui ʻana i ka nui o ka Nickel e hāʻawi i ka pale ʻana i ka carburization.

Hoʻohana nui ʻia nā kila kila Austenitic no ka lawelawe ʻana a hiki i ka haʻahaʻa haʻahaʻa e like me ka wela helium wai (-269 deg C). ʻO ka hapa nui kēia ma muli o ka nele o kahi hoʻololi i wehewehe ʻia mai ka ductile i ka brittle fracture i ka hoʻāʻo ʻana i ka paʻakikī.

Ana 'ia ka 'o'ole'a ma ka ho'opili 'ana i kahi la'ana li'ili'i me ka hāmare kowali. ʻO ka mamao a ka hāmare e koli ai ma hope o ka hopena, he ana ia o ka paʻakikī. ʻO ka pōkole o ka mamao, ʻoi aku ka paʻakikī o ke kila e like me ka ikehu o ka hāmare e komo ʻia e ka hāpana. Ua ana ʻia ka paʻakikī ma Joules (J). Kuhi ʻia nā waiwai liʻiliʻi o ka paʻakikī no nā noi like ʻole. Manaʻo ʻia ka waiwai o 40 J he kūpono no ka hapa nui o nā kūlana lawelawe.

Hōʻike nā kila me nā hale ferritic a i ʻole martensitic i ka hoʻololi koke ʻana mai ka ductile (palekana) i ka haki ʻana (palekana) ma luna o kahi ʻokoʻa liʻiliʻi o ka wela. ʻO ka maikaʻi loa o kēia mau kila e hōʻike ana i kēia ʻano ma nā mahana ʻoi aku ka kiʻekiʻe ma mua o -100 deg C a ma nā manawa he nui wale nō ma lalo o ka ʻole.

ʻO ka ʻokoʻa o nā kila austenitic e hōʻike wale ana i ka hāʻule mālie i ka waiwai o ka paʻakikī hopena a ʻoi aku ka maikaʻi ma luna o 100 J ma -196 deg C.

ʻO kekahi kumu e pili ana i ke koho ʻana i ke kila ma ka haʻahaʻa haʻahaʻa ka hiki ke pale i ka hoʻololi ʻana mai austenite a martensite.

Ua ʻōlelo maʻamau ʻo "ʻaʻole magnetik ke kila kila". ʻAʻole pololei kēia a ʻoi aku ka paʻakikī o ke kūlana maoli. Loaʻa ka degere o ka pane magnetic a i ʻole ka permeability magnetic mai ka microstructure o ke kila. ʻO kahi mea ʻole-magnetic loa i loaʻa i ka pili magnetic permeability o 1. ʻO nā hale Austenitic ʻaʻole loa-magnetic a no laila e loaʻa i kahi 100% austenitic stainless steel ka permeability o 1. I ka hoʻomaʻamaʻa ʻaʻole i hoʻokō ʻia kēia. Loaʻa mau ka liʻiliʻi o ka ferrite a / a i ʻole martensite i loko o ke kila a no laila ʻoi aku ka nui o nā waiwai permeability ma luna o 1. ʻO nā waiwai maʻamau no nā kila kila austenitic maʻamau hiki ke hoʻonohonoho i ka 1.05 - 1.1.

Hiki ke hoʻololi ʻia ka permeability magnetic o nā kila austenitic i ka wā e hana ai. No ka laʻana, ʻo ka hana anu a me ka welding e hoʻonui i ka nui o ka martensite a me ka ferrite i loko o ke kila. ʻO kahi laʻana maʻamau i loko o kahi paila kila kila kahi i liʻiliʻi ai ka pane hoʻoheheʻe ʻana o ka wai palahalaha akā ʻoi aku ka kiʻekiʻe o ke kīʻaha i kaomi ʻia ma muli o ke kūkulu ʻia ʻana o ka martensite ma nā kihi.

Ma nā ʻōlelo kūpono, hoʻohana ʻia nā kila kuhili ʻole austenitic no nā noi "non-magnetic", no ka laʻana, ka magnetic resonance imaging (MRI). I kēia mau hihia, pono pinepine e ʻae i ka permeability magnetic kiʻekiʻe ma waena o ka mea kūʻai aku a me ka mea hoʻolako. Hiki ke emi me 1.004.

Martensitic, ferritic, duplex and precipitation hardening steels he magnetic.

Hoʻokaʻawale ʻia ke kila kila i 5 mau ʻano:

1. Ferritic - Hoʻokumu ʻia kēia mau mea kila ma Chromium me ka liʻiliʻi o Carbon maʻamau ma lalo o 0.10%. ʻO kēia mau kila he microstructure like me ke kalapona a me nā kila hao haʻahaʻa. Hoʻohana pinepine ʻia lākou i nā ʻāpana lahilahi ma muli o ka nele o ka paʻakikī i nā welds. Eia naʻe, inā ʻaʻole koi ʻia ka welding, hāʻawi lākou i kahi ākea o nā noi. ʻAʻole hiki iā lākou ke paʻakikī e ka mālama wela. Hiki ke hoʻohana ʻia nā kila Chromium kiʻekiʻe me nā hoʻohui o Molybdenum i nā kūlana koʻikoʻi e like me ka wai kai. Ua koho ʻia nā kila Ferritic no ko lākou kūʻē ʻana i ke koʻikoʻi o ka ʻāʻī ʻana. ʻAʻole hiki ke hoʻohālikelike ʻia e like me nā kila stainless austenitic. He magnetic lākou.
2.Austenitic - ʻO kēia mau kila ka mea maʻamau. Loaʻa kā lākou microstructure mai ka hoʻohui ʻana o Nickel, Manganese a me Nitrogen. ʻO ia ke ʻano like me ka hana ʻana i nā kila maʻamau i nā wela kiʻekiʻe. Hāʻawi kēia ʻano i kēia mau kila i kā lākou hui pū ʻana o ka weldability a me ka formability. Hiki ke hoʻonui ʻia ka pale ʻana i ka corrosion ma ka hoʻohui ʻana i ka Chromium, Molybdenum a me Nitrogen. ʻAʻole hiki iā lākou ke hoʻopaʻakikī ʻia e ka mālama wela akā loaʻa iā lākou ka waiwai o ka hiki ke hoʻopaʻakikī i ka hana a hiki i nā pae ikaika kiʻekiʻe me ka mālama ʻana i kahi pae kūpono o ka ductility a me ka paʻakikī. Pilikia nā kila austenitic maʻamau i ka pohā ʻino. ʻO nā kila austenitic nickel kiʻekiʻe ua hoʻonui i ke kūpaʻa ʻana i ke koʻikoʻi o ka pohā ʻino. ʻAʻole lākou ma ke ʻano he magnetic akā hōʻike pinepine ʻia kekahi pane magnetic ma muli o ka haku mele a me ka paʻakikī o ka hana o ke kila.
3.Martensitic - Ua like kēia mau kila me nā kila ferritic i hoʻokumu ʻia ma Chromium akā ʻoi aku ka kiʻekiʻe o ka pae Carbon a hiki i ka 1%. ʻO kēia ka mea e hiki ai iā lākou ke paʻakikī a hoʻonāukiuki e like me ke kalapona a me nā kila haʻahaʻa. Hoʻohana ʻia lākou i kahi e koi ʻia ai ka ikaika kiʻekiʻe a me ka pale corrosion maʻalahi. ʻOi aku ka maʻamau i nā huahana lōʻihi ma mua o ke ʻano o ka pepa a me ka pā. Loaʻa iā lākou ka haʻahaʻa weldability a me ka formability. He magnetic lākou.
4.Duplex - He microstructure kēia mau kila ma kahi o 50% ferritic a me 50% austenitic. Hāʻawi kēia iā lākou i ka ikaika kiʻekiʻe ma mua o nā kila ferritic a i ʻole austenitic. Kūleʻa lākou i ke koʻikoʻi o ka corrosion cracking. No laila ua kapa ʻia nā kila "lean duplex" i hoʻohālikelike ʻia i ke kūpaʻa ʻino i nā kila austenitic maʻamau akā me ka ikaika i hoʻonui ʻia a me ke kūpaʻa ʻana i ka pohā ʻino. ʻO nā kila "Superduplex" i hoʻonui i ka ikaika a me ke kū'ēʻana i nāʻano corrosion a pau i hoʻohālikelikeʻia me nā kila austenitic maʻamau. Hiki iā lākou ke weld akā pono e mālama i ke koho ʻana i nā mea hoʻohana wili a me ka hoʻokomo wela. Loaʻa iā lākou ka formability haʻahaʻa. He magnetic lākou akā ʻaʻole like me ka ferritic, martensitic a me nā māka PH ma muli o ka 50% austenitic phase.
5.Precipitation hardening (PH) - Hiki i kēia mau kila ke hoʻoikaika i ka ikaika kiʻekiʻe loa ma ka hoʻohuiʻana i nā mea e like me Copper, Niobium a me Aluminum i ke kila. Me ka hoʻomaʻamaʻa wela "ʻelemakule" kūpono, hana ʻia nā ʻāpana maikaʻi loa i loko o ka matrix o ke kila e hāʻawi i ka ikaika. Hiki ke hana ʻia kēia mau kila i nā ʻano ʻano paʻakikī e koi ana i ka hoʻomanawanui maikaʻi ma mua o ka hoʻomaʻamaʻa ʻana i ka wā kahiko no ka mea he liʻiliʻi ka distortion mai ka mālama hope ʻana. He ʻokoʻa kēia i ka hoʻopaʻapaʻa maʻamau a me ka hoʻoulu ʻana i nā kila martensitic kahi i pilikia ai ka distortion. Hoʻohālikelike ʻia ke kūpaʻa corrosion me nā kila austenitic maʻamau e like me 1.4301 (304).

 ʻO nā ʻano maʻamau o ka corrosion ma ke kila kila:

Pitting corrosion - Hiki ke hoʻouka ʻia ka papa passive ma ke kila kila e kekahi ʻano kemika. ʻO ka chloride ion Cl- ka mea maʻamau o ia mau mea a loaʻa i loko o nā mea o kēlā me kēia lā e like me ka paʻakai a me ka bleach. Hōʻalo ʻia ka ʻino ʻana o ka lua ma ka hōʻoia ʻana ʻaʻole e pili lōʻihi ke kila kila me nā kemika ʻino a i ʻole ma ke koho ʻana i kahi ʻano kila i ʻoi aku ka pale ʻana i ka hoʻouka ʻana. Hiki ke loiloi ʻia ke kūʻē ʻana o ka pitting me ka hoʻohana ʻana i ka Pitting Resistance Equivalent Number i helu ʻia mai ka ʻike alloy.
Crevice corrosion - Pono ke kila kila i ka hāʻawi ʻana i ka oxygen e hōʻoia i ka hiki ke hana ʻia ka papa passive ma ka ʻili. I loko o nā māwae paʻa loa, ʻaʻole hiki i ka oxygen ke komo i ka ʻili kila kuhili ʻole i hiki ke hoʻouka ʻia. Hōʻalo ʻia ka ʻino ʻino ʻana ma o ka hoʻopaʻa ʻana i nā ʻāwaha me kahi sealant maʻalahi a i ʻole ma ka hoʻohana ʻana i kahi papa kūpaʻa ʻoi aku ka corrosion.
ʻAiʻino maʻamau - ʻAʻole e ʻino like ke kila kuhili ʻole e like me ke kalapona maʻamau a me nā kila hao. Eia nō naʻe, me kekahi mau kemika, ʻoi aku ka nui o nā waikawa, hiki ke hoʻouka like ʻia ka papa passive ma muli o ka noʻonoʻo ʻana a me ka mahana a ua puʻunaue ʻia ka poho metala ma luna o ka ʻili holoʻokoʻa o ke kila. ʻO ka waika hydrochloric a me ka ʻakika sulfuric i kekahi mau haʻahaʻa he mea ʻino loa i ke kila kila.
Stress corrosion cracking (SCC) - He ʻano kakaikahi kēia o ka corrosion e koi ana i kahi hui kikoʻī o ke koʻikoʻi tensile, ka mahana a me nā ʻano mea ʻino, pinepine ka chloride ion, no ia mea. ʻO nā noi maʻamau kahi e hiki mai ai ka SCC he pahu wai wela a me nā loko ʻauʻau. ʻO kekahi ʻano i kapa ʻia ʻo sulphide stress corrosion cracking (SSCC) pili me ka hydrogen sulphide i ka ʻimi ʻaila a me ke kinoea a me ka hana ʻana.
Intergranular corrosion - He ʻano kakaikahi kēia o ka corrosion. Inā kiʻekiʻe loa ka pae Carbon i ke kila, hiki i ka Chromium ke hui pū me Carbon e hana i ka Chromium Carbide. Hana ʻia kēia ma nā mahana ma waena o 450-850 deg C. Ua kapa ʻia kēia kaʻina hana sensitization a hana maʻamau i ka wā wili. ʻO ka Chromium i loaʻa e hana i ka papa passive ua hoʻemi maikaʻi ʻia a hiki ke hiki ke ʻino. Hōʻalo ʻia ma ke koho ʻana i kahi māka kalapona haʻahaʻa i kapa ʻia nā māka 'L' a i ʻole ma ka hoʻohana ʻana i ke kila me Titanium a i ʻole Niobium e hui pū me Carbon.
ʻAiʻino Galvanic - Inā pili ʻelua metala ʻokoʻa kekahi i kekahi a me kahi electrolyte e laʻa me ka wai a i ʻole ka hopena ʻē aʻe, hiki ke hoʻonohonoho ʻia ke kelepona galvanic. Ua like kēia me ka pākaukau a hiki ke hoʻolalelale i ka corrosion o ka metala liʻiliʻi. Hiki ke pale ʻia ma ka hoʻokaʻawale ʻana i nā metala me kahi insulator non-metallic e like me ka lāʻau.

ʻOiai ʻoi aku ka paʻa o ke kila kila i ka ʻino ma mua o ke kalapona maʻamau a i ʻole ke kila kila, i kekahi mau kūlana hiki ke ʻino. ʻAʻole ia he 'stain-less' ʻaʻole 'stain-impossible'. Ma ka lewa maʻamau a i ʻole ka wai, ʻaʻole e ʻino ke kila kila e like me ka mea i hōʻike ʻia e nā ʻāpana kuʻi hale, nā ʻoki ʻoki, nā ipu a me nā papa hana.

Ua manaʻo nui ʻia ua ʻike ʻia ke kila kila i ka makahiki 1913 e Sheffield metallurgist Harry Brearley. Ua hoʻāʻo ʻo ia me nā ʻano kila like ʻole no nā mea kaua a ʻike ʻo ia ʻaʻole i ʻino ʻia kahi kila Chromium 13% ma hope o kekahi mau mahina.