ʻO nā pūnāwai kuhiliʻole ka mākēneki?
ʻAʻole maʻalahi ka ʻae a ʻaʻole ka nīnau inā he magnetic nā puna kila kuhiliʻole. Pili maoli ia i ke ʻano kikoʻī o ke kila kila i hoʻohana ʻia. ʻO kekahi, some aren't, a hiki i kekahi ke lilo i magnetic ma o ka hana ʻana.
Inā paha punawai kila kuhiliʻole[^1] pili loa ka magnetic ma ke ʻano kikoʻī a i ʻole ka pae o ke kila kila. Austenitic kila kila (like 302, 304, 316) he mau non-magnetic[^ 2] i ko lakou kulana annealed, ʻoiai hiki iā lākou ke lilo i mea magnetic ma hope o ka hana anu, ka mea maʻamau i hana puna[^ 3]. Na kila kuhiliʻole Martensitic (like 410, 420) a me ka paʻakikī o ka ua (PH) nā kila kila (like 17-7 PH) He mea magnetic ma muli o ko lākou mau hana crystalline. No laila, ʻaʻole hiki iā ʻoe ke hilinaʻi wale ma luna o kahi hoʻāʻo magnet[^4] e hoʻomaopopo pono i nā mea a pau punawai kila kuhiliʻole[^1], no ka mea, ʻaʻole ʻae ka pane magnetic i kekahi mau māka kuhili.
I've seen many customers confused by this. Manaʻo lākou ʻaʻole magnetik nā kila kuhili ʻole a pau, a i ko lakou "stainless" pili ka puna i ka magnet, they immediately think it's not stainless at all. It's important to understand the metallurgy to avoid misjudgment.
Why Some Stainless Steels Are Magnetic and Others Aren't
Hele mai nā mea a pau i ka hoʻolālā aniani.
ʻO ka magnetism o punawai kila kuhiliʻole[^1] ua hoʻoholo ʻia e ko lākou ʻano aniani i loko, ka mea i hoopiliia e ko lakou haku mele[^5] a me ka hana ana. Austenitic kila kila[^6] ʻo ka mea nui non-magnetic[^ 2] no ka mea, loaʻa iā lākou a cubic alo-waena[^7] (FCC) hale aniani, ka mea i nele i ka ferronā waiwai māke[^8]. He ʻokoʻa, martensitic a me ka ferritic kuhiliʻole kila ma muli o ko lākou kino-waena cubic (BCC) hale aniani, ka mea e hiki ai ke hana ferromagnetic. ʻO ka hana ʻana e like me ka hana anu hiki ke hoʻoulu i ka magnetism liʻiliʻi i kekahi mau māka austenitic ma ka hoʻololi ʻana i kahi ʻāpana o kā lākou hale i martensite..
It's a fascinating bit of materials science. ʻO ka hoʻonohonoho liʻiliʻi o nā ʻātoma i loko o ka metala e hoʻololi nui i ke ʻano o kāna hana me kahi magnet maʻalahi.
1. Austenitic Kuhiliʻole (ʻO ka maʻamau Non-Magnetic)
ʻO kēia nā mea maʻamau non-magnetic[^ 2] nā kila kila.
| Stainless Steel Type | Nā ʻElemu Alloying Primary | Hoʻokumu Crystal | Waiwai Magnetic (Hana ʻia) | Waiwai Magnetic (Hana ʻia ke anu no nā pūnāwai) | Nā Papa Maʻamau (Puna) |
|---|---|---|---|---|---|
| Austenitic Stainless Steel | Chromium, Nikela, (Manganese) | Kubiki Kaulana Maka (FCC) | Non-Magnetic | Mākēneki iki (ma muli o ka martensite i hoʻopaʻa ʻia) | ʻAno 302, 304, 316 |
Austenitic kila kila[^6] ʻo ia nā ʻano mea i hoʻohana nui ʻia no nā pūnāwai i ka wā non-magnetic[^ 2]c waiwai](https://www.carpentertechnology.com/blog/magnetic-properties-of-stainless-steels)[^8] a i ʻole e koi ʻia ke kūpaʻa corrosion maikaʻi. Loaʻa iā lākou nā māka e like me Type 302, 304, a 316.
- Hoʻohui Kimia: Loaʻa i kēia mau kila ka nui o ka chromium a me ka nickel (a i kekahi manawa ka manganese a me ka nitrogen). He kī nui ka ʻike nickel i ka hoʻopaʻa ʻana i kā lākou microstructure austenitic.
- Hoʻokumu Crystal: Austenitic kila kila[^6] loaa a cubic alo-waena[^7] (FCC) hale aniani. ʻO kēia hoʻonohonoho kikoʻī o nā mana he ʻano non-ferromagnetic. I kā lākou hoʻopili piha ʻana (palupalu loa) mokuʻāina, pono kēia mau māka non-magnetic[^ 2].
- Ka hopena o ka hana anu (Hana Puna): Here's where it gets a bit nuanced. E hana i puna, pono e hana anu ka uwea (huki ʻia ma o nā make a ʻōwili ʻia paha) e hoʻokō i ka ikaika tensile kiʻekiʻe e pono ai a me ka wela puna. ʻO kēia hana anu[^9] Hoʻoulu ke kaʻina hana i ke koʻikoʻi a hiki ke hoʻololi i kahi ʻāpana o ka hale austenitic i kahi liʻiliʻi loa martensite, ka mea ʻo ia mākia.
- Ka hopena: No laila, he puna kila kuhiliʻole austenitic (like 302 a i ʻole 304) ka mea i hana anu no ka loaʻa ʻana o nā waiwai puna e hōʻike maʻamau a hoʻomeamea ʻuʻuku liʻiliʻi. It won't stick to a strong magnet as firmly as carbon steel, akā e manaʻo ʻoe i kahi huki paʻa. The more severe the cold work, ʻoi aku ka ʻoi aku o ka magnetic.
- Noi: Koho ʻia kēia mau māka i ka wā maikaʻi pale ʻino[^10] pono, a pono ka palapala noi a non-magnetic[^ 2] a i ʻole mea haʻahaʻa haʻahaʻa-magnetic (E.g., i nā lako uila koʻikoʻi a i ʻole Nā Pūnaewele Pūnaewele[^11] kahi e pilikia ai ka hoʻopili magnetic ikaika).
Mai koʻu ʻike, ina he puna i hanaia mai 302 a i ʻole 304 pau loa non-magnetic[^ 2], it hasn't been properly cold-worked to spring temper. ʻO kahi punawai austenitic stainless steel maikaʻi e ʻaneʻane e loaʻa i kahi pane magnetic liʻiliʻi.
2. Na kila kuhiliʻole Martensitic (Magnetic)
He mea magnetic a paakiki keia.
| Stainless Steel Type | Nā ʻElemu Alloying Primary | Hoʻokumu Crystal | Waiwai Magnetic | Nā Papa Maʻamau (Puna) |
|---|---|---|---|---|
| He kila kila ʻole Martensitic | Chromium, Kalapona | Kubiki Kikowaena Kino (BCC) | Mākēneki ikaika | ʻAno 410, 420 |
Hoʻolālā ʻia nā kila stainless Martensitic no ka paʻakikī kiʻekiʻe a me ka ikaika, a he mau mea hoʻopaneʻe lākou. Aia nā māka puna maʻamau i ke ʻano 410 a 420.
- Hoʻohui Kimia: Loaʻa i kēia mau kila ka chromium nui akā ma ke ʻano he nickel haʻahaʻa. ʻO ke koʻikoʻi, ʻoi aku ka nui o nā kalapona i hoʻohālikelike ʻia me nā māka austenitic, hiki iā lākou ke hoʻomaʻamaʻa wela e loaʻa i ka paʻakikī kiʻekiʻe loa.
- Hoʻokumu Crystal: Loaʻa nā kila kuhili martensitic a cubic pili kino[^12] (BCC) a i ʻole tetragonal e pili ana i ke kino (BCT) hale aniani. He ferromagnetic kēia hale, ʻo ia hoʻi kēia mau kila mākia ikaika ma nā kūlana a pau (i hoʻopili ʻia, paakiki, a i ʻole ma ke ʻano puna).
- Noi: Hoʻohana ʻia lākou no nā pūnāwai kahi ikaika kiʻekiʻe, paakiki, a ʻo ke kūpale ʻaʻahu ka mea nui, a ʻae ʻia a koi ʻia paha kahi pane magnetic. ʻO kā lākou pale ʻino[^10] ʻoi aku ka haʻahaʻa ma mua o nā māka austenitic a i ʻole PH, ʻaʻole kūpono iā lākou no nā kaiapuni corrosive koʻikoʻi.
Ke makemake ka mea kūʻai i kahi paʻakikī loa, pūnāwai kuhili ʻole e kūʻē i ka ʻaʻahu, Nānā au i nā māka martensitic. Hāʻawi lākou i ka ikaika akā hele mai me kahi pūlima magnetic.
3. Ka ua-paakiki (PH) Na kila kila (Magnetic)
ʻO ke koho magnetic kiʻekiʻe.
| Stainless Steel Type | Nā ʻElemu Alloying Primary | Hoʻokumu Crystal | Waiwai Magnetic | Nā Papa Maʻamau (Puna) |
|---|---|---|---|---|
| Ka ua-paakiki (PH) Kila kohu ʻole | Chromium, Nikela, keleawe, (Aluminum) | Kubiki Kikowaena Kino (BCC) | Mākēneki ikaika | 17-7 PH, 17-4 PH |
ʻO ka ua-paʻakikī (PH) ʻike ʻia nā kila kila no ko lākou ikaika a maikaʻi pale ʻino[^10], a he mau mane no hoi. ʻO ka papa puna maʻamau 17-7 PH.
- Hoʻohui Kimia: ʻO kēia mau mea kila he mau mea paʻakikī i loaʻa ka chromium, nikela, a pinepine nā mea ʻē aʻe e like me ke keleawe a i ʻole ka aluminika. ʻO kā lākou hana kūikawā e hiki ai iā lākou ke paʻakikī ma o ke kaʻina hana hoʻomalu wela haʻahaʻa (paʻakikī o ka ua), ʻo ia ka mea e hoʻoheheʻe ai i loko o ka microstructure.
- Hoʻokumu Crystal: ʻOiai e hoʻomaka paha kekahi mau kila PH me kahi ʻano austenitic, ʻO kā lākou hana paʻakikī hope loa e pili ana i ka nui o ka martensite a i ʻole kahi ʻano like ʻole BCC. Hana kēia iā lākou mākia ikaika.
- Noi: Ua koho ʻia nā kila kila PH no nā noi puna nui loa kahi ikaika kiʻekiʻe, ola luhi maikaʻi, a maikaʻi pale ʻino[^10] koi ʻia, e like me ka aerospace, koʻikoʻi Nā Pūnaewele Pūnaewele[^11], a i ʻole nā mea hana ʻoihana kiʻekiʻe. ʻO ko lākou ʻano magnetic he ʻano ʻae ʻia i hāʻawi ʻia i ko lākou mau ʻano mechanical kiʻekiʻe.
No nā koi ikaika loa, 17-7 ʻO PH kaʻu hele pinepine. Hāʻawi ia i ka hana kupaianaha, akā pono e hoʻomaopopo nā mea kūʻai aku e pili pono ana ia i kahi magnet.
Nā hopena no ka ʻike a me ka hoʻohana ʻana
ʻO ka hoʻomaopopo ʻana i ka magnetism kōkua e pale i ka kuhi hewa.
Ka hoomaopopo ana i ka nā waiwai māke[^8] He mea koʻikoʻi nā ʻano ʻano pūnāwai stainless steel ʻē aʻe no ka ʻike pono ʻana o nā mea a me ka noi kūpono. Hiki i ka ho'āʻo magnet ke hoʻopau maikaʻi i ke kila kuhiliʻi austenitic inā ikaika ka mana o kahi puna, akā, ʻaʻole hiki iā ia ke hoʻokaʻawale i waena o nā kila kila kila (martensitic, PH) a me ke kila kalapona. No nā noi e koi ikaika ana non-magnetic[^ 2]c waiwai](https://www.carpentertechnology.com/blog/magnetic-properties-of-stainless-steels)[^8], ʻO nā māka austenitic wale nō ke kūpono, a ia manawa, kekahi magnetism iki ma hope hana anu[^9] pono e noonooia. ʻO ka ʻokoʻa, no nā noi i ʻae ʻia ka magnetism, Hāʻawi nā kila kuhili ʻole magnetic i nā koho ikaika ʻoi aku. ʻIke mea kūpono, koi pinepine ma mua o ka a hoʻāʻo magnet[^4], he mea nui e hōʻoia i ka hoʻokō ʻana o ka puna i nā koi ʻelua a me nā koi kūlohelohe.
ʻOi aku kēia ʻike ma mua o ka ʻike kula; loaʻa iā ia nā hopena honua maoli i ka hoʻolālā puna a me ka noi.
1. ʻIke Mea
Don't let magnetism confuse you.
| Ka hopena hoao (Mākēneki) | He aha ia e haʻi ai iā ʻoe | He aha paha ia (Pono no ka imi hou ana) |
|---|---|---|
| Non-Magnetic / Nawaliwali loa Magnetic | ʻO ke kila kila Austenitic paha (E.g., 302, 304, 316). | ʻO ke kūlana kiʻekiʻe o ka 300-series stainless steel. |
| Mākēneki ikaika | AOLE Austenitic Stainless Steel (302/304/316). | ʻAihue kīwī, He kila kila ʻole Martensitic (410/420), a i ʻole PH kila kila (17-7 PH). |
'Ōlelo hoʻāʻo magnet[^4] he hana mua maʻamau i ka ʻike ʻana i ke kila kila, akā, pono e wehewehe pololei ʻia nā hopena.
- Non-Magnetic (a i ʻole ka nawaliwali loa): Inā hōʻike liʻiliʻi ka manaʻo o kahi pūnāwai i kahi magnet, ʻaneʻane maopopo he austenitic stainless steel (like 302, 304, 316). He hōʻailona ikaika kēia o kāna ʻohana papa.
- Mākēneki ikaika: Inā huki ikaika ka pūnāwai i kahi magnet, ʻo ia ʻAʻole loa he kila kuhili ʻole austenitic like 302, 304, a i ʻole 316. Akā naʻe,, hiki paha:
- ʻAihue kīwī: ʻO ka mea maʻamau maʻamau punawai puna.
- He kila kila ʻole Martensitic (E.g., 410, 420): Na kila kuhiliʻole mākēneki.
- He kila kuhili ʻole ka ua-paʻakikī (E.g., 17-7 PH): ʻO nā kila kuhili ʻole hoʻi.
- Ka hopena no nā Puna Mākēneki: ʻAʻole hiki ke ʻike maopopo ʻia kahi pūnāwai mākēneki ikaika he kila kalapona a i ʻole he kila kila kila ma ka hoʻāʻo magnet wale nō. Nā ho'āʻo hou aku, like a hoʻāʻo ʻōhū[^13] a i ʻole Nānā XRF[^14], pono e hoʻokaʻawale i waena o kēia mau mea.
ʻO kaʻu mea lawe nui ma ʻaneʻi ʻo ia a hoʻāʻo magnet[^4] maikaʻi loa no e hoopau ana 300-series stainless if it's strongly magnetic. But it's not a standalone test for identifying all stainless steels.
2. Noonoo Noi
Hiki i ka Magnetism ke lilo i waiwai koʻikoʻi ma kekahi mau kahua.
| ʻAno noi | Koi waiwai Magnetic | Nā Papa Kūleʻa Kūleʻa No nā Puna | Kumukumu |
|---|---|---|---|
| ʻEleke Pilikino / Na Lapaau Lapaau | Non-Magnetic | Austenitic Stainless Steel (302, 304, 316). | Hōʻalo i ka hoʻopilikia ʻana i nā hōʻailona uila a i ʻole nā mea hana kiʻi. |
| Kiekie Mahana / Koʻikoʻi Kiʻekiʻe | ʻAe pinepine ʻia ka waiwai magnetik | Martensitic (410/420) a i ʻole PH (17-7 PH) Kila kohu ʻole. | Hoʻokumu mua i ka ikaika a me ka pale wela ma mua o ka non-magnetism. |
| ʻOihana Nui / Kalepa | ʻAʻole koʻikoʻi ka waiwai magnetic | Kekahi papa kila kuhiliʻole kūpono | ʻO nā pilikia nui ka corrosion, ikaika, a me ke kumukuai. |
| ʻO ke kiʻi kiʻi magnetic / ʻIke ʻana | Magnetic | ʻO Martensitic a i ʻole PH Kuhili ʻole. | Pono e ʻike ʻia ka puna ponoʻī e nā mea ʻike magnetic. |
'Ōlelo nā waiwai māke[^8] o ka puna kila kuhiliʻole hiki ke lilo i mea koʻikoʻi i kekahi mau noi.
- Nā Koina Mākēneki ʻole:
- ʻEleke Pilikino: Ma nā ʻāpana kokoke i nā mea ʻike, paʻa paʻa, a i ʻole nā mea uila ʻē aʻe, hiki i nā māla magnetic ikaika ke hoʻopilikia.
- Lako Lapaau: I nā implants lapaʻau, Nā mīkini MRI, a i ʻole nā mea hana diagnostic ʻē aʻe, non-magnetic[^ 2] pono pinepine nā mea i mea e pale ai i ka haunaele.
- Koho: No kēia mau noi, austenitic stainless steels (302, 304, 316) makemake ʻia. Hōʻike pinepine nā mea hoʻolālā i kēia mau māka me ka ʻike ʻoiai he liʻiliʻi paha nā pūnāwai i hana ʻia pane magnetic[^15], ʻo ka mea maʻamau i loko o nā palena kūpono.
- ʻAe ʻia/makemake ʻia nā ʻano Magnetic:
- Hoohana Hana Hana Nui: No ka nui o nā noi ʻoihana, ʻaʻole pili ka punawai a i ʻole ʻole; aia ka manao pale ʻino[^10], ikaika, a me ke kumukuai.
- Nā noi ikaika kiʻekiʻe: Inā makemake ʻia ka ikaika kiʻekiʻe loa, martensitic (410/420) a i ʻole PH (17-7 PH) nā kila kila hiki ke koho, ʻoiai lākou he magnetic, no ka mea, ua oi aku ko lakou mau waiwai ma mua o ka noonoo magnetic.
- ʻIke Magnetic: I nā hihia kakaikahi, Pono paha ka punawai he magnetic no ka ʻike ʻana (E.g., e ka mea ike makamaka).
I ka hoʻolālā puna, ʻO ka magnetism kahi waiwai waiwai ʻē aʻe e noʻonoʻo ai. It's never the wale nō noonoo ana, akā hiki ke lilo i mea koʻikoʻi no nā noi kikoʻī.
Hopena
ʻAʻole ʻo nā pūnāwai kila kuhili ʻole a pau. Nā māka Austenitic (302, 304, 316) ʻAʻole maʻamau akā hiki ke lilo i mea hoʻokalakupua ma hope hana anu[^9] no ka wela puna. Martensitic (410, 420) a me ka paʻakikī o ka ua (17-7 PH) ʻO nā kila kuhiliʻole he mea magnetic. He mea koʻikoʻi kēia ʻokoʻa no ka ʻike ʻana i nā mea, me he hoʻāʻo magnet[^4] ʻaʻole lawa ka hoʻopaʻa ʻana i nā ʻano kila kuhili ʻole, a no nā noi pili i ka hoʻopili magnetic, i hea non-magnetic[^ 2] makemake ʻia nā māka austenitic.
No ka mea hoʻokumu
Ua hoʻokumu ʻia ʻo LinSpring e Mr. David Lin, he ʻenekinia me ka hoihoi lōʻihi i ka mīkini puna
[^1]: E ʻimi i kēia loulou no ka hoʻomaopopo ʻana i nā waiwai magnetic o nā pūnāwai kila kila a me kā lākou mau noi.
[^ 2]: E hoʻomaopopo i ka hopena o nā waiwai non-magnetic i nā noi kila kuhiliʻole.
[^ 3]: E ʻimi i nā kaʻina hana e pili ana i ka hana ʻana i nā pūnāwai kuhili ʻole a me ko lākou hopena.
[^4]: E aʻo e pili ana i ka maikaʻi o ka hoʻāʻo magnet i ka ʻike ʻana i nā ʻano like ʻole o ke kila kila.
[^5]: E ʻimi i ka pili ʻana o ka haku mele ʻana i nā waiwai magnetic o ke kila kila.
[^6]: E aʻo e pili ana i nā kila kuhili ʻole Austenitic a me ke kumu he mea maʻamau ʻole ia.
[^7]: E ʻike i ke koʻikoʻi o ka hoʻolālā cubic i waena o ke alo i ka hoʻoholo ʻana i ka magnetism.
[^8]: E hoʻomaopopo i nā ʻano mea magnetic o nā ʻano kila kuhili ʻole.
[^9]: E aʻo pehea e hiki ai i ka hana anu ke hoʻoulu i ka magnetism i nā kila stainless austenitic.
[^10]: E ʻimi i ke koʻikoʻi o ka pale ʻana i ka corrosion i ke koho ʻana i ke kila kila no nā pūnāwai.
[^11]: E ʻimi i ke koʻikoʻi o ke koho ʻana i nā mea i loko o nā mea lapaʻau, e kālele ana i nā koho non-magnetic.
[^12]: E hoʻomaopopo i ke ʻano o ka hoʻokumu ʻana o ke kino-centered cubic i ka waiwai magnetic o nā kila kila.
[^13]: E aʻo e pili ana i ka hoʻāʻo ʻana a me kāna kuleana i ka ʻike ʻana i nā ʻano ʻano kila kila.
[^14]: E ʻike pehea e hiki ai i ka loiloi XRF ke kōkua i ka ʻike pololei ʻana i nā ʻano kila kuhiliʻole.
[^15]: E ʻike i ke ʻano o ka pane ʻana o nā māka kila kila i nā hoʻokolohua magnetic.