1. Hōʻikeʻike
I ka metala kila o kēia wā, ʻO nā mea hoʻohuihui e kuhikuhi i ka mechanical o kahi mea, Kekau, hana thermal.
I waena o kēia mau, nitrogen (N) kū i waho ma ke ʻano he pahikaua makalua.
Ma kekahi lima, hāʻawi ʻo ia i ka hoʻoikaika ʻokoʻa, ʻO ka lepo lepo, a me nā pono kū'ē i ka corrosion; ma kekahi, hiki iā ia ke hoʻopaneʻe i ka embrittlement, Potiwale, a me nā hemahema wili.
NOEHUI, ʻO ka mālama ʻana i ka ʻano o ka nitrogen-a me ka hoʻomalu ʻana i kāna ʻike me ka pololei-ua lilo i mea koʻikoʻi no nā mea hana kila a puni ka honua.
Ke nānā nei kēia ʻatikala i ka hana multifaceted o ka nitrogen i ke kila, hui ʻana i ka ʻepekema kumu, ʻikepili honua maoli, a me nā hana ʻoihana maikaʻi loa e hōʻike a Pūnaewele, moo kakahtia, a hilinaʻi kuʻuna.
2. Nā kumu kumu o ka Nitrogen i ka hao a me ke kila
ʻO ka hoʻomaopopo ʻana i ke ʻano o ka nitrogen i ke kila pono e nānā i kona mau ʻano, palena solubility, ka launa pū me nā mea ʻē aʻe, a me nā ʻano analytical.
Ma keia mau pauku, ʻimi mākou i kēlā me kēia ʻaoʻao e kūkulu i kumu paʻa no ka hoʻokele pono a me ka hoʻolālā metallurgical.
Nā ʻano a me ka hāʻawi ʻana i ka Nitrogen
Ka mua, ʻike ʻia ka nitrogen i ʻekolu mau mokuʻāina nui i loko o ke kila hoʻoheheʻe a paʻa:
- Nitrogen Hoʻoheheʻe Interstitially
Noho nā ʻātoma Nitrogen i nā wahi octahedral i loko o ka lattice hao— ʻelua cubic i waena o ka maka. (austentes) a me ka cubic pili kino (ferrite).
I ka ʻoiaʻiʻo, a 1200 ° C a 1 atm, hoʻoheheʻe austenite a hiki i 0.11 wt% N, ʻoiai ʻo ka ferrite e hoʻokomo i ka liʻiliʻi ma mua o 0.01 wt% ma lalo o nā kūlana like. - ʻO Nitride Precipitates
Ke ma'alili ke kila, ʻO nā mea hana nitride ikaika e like me ka titanium a me ka hoʻopaʻa alumini i hoʻoheheʻe ʻia i ka N e hana i nā ʻāpana maikaʻi (20–100 nm).
ʻo kahi laʻana, Hōʻike ʻo AlN a me TiN i nā ikehu manuahi o –160 kJ/mol a me –184 kJ/mol ma 1000 ° C, Pauliu, ʻo ia ka mea e paʻa loa ai a maikaʻi hoʻi nā wahi pinning palena palaoa. - Nitrogen kinoea (N₂) Nā ʻeke
Inā ʻoi aku ka nui o ka solubility i ka wā paʻa, hiki iā ia ke hoʻoheheʻe ʻia e like me nā ʻōpū N₂.
ʻOiai he haʻahaʻa 0.015 wt% o N i hoʻoheheʻe ʻia hiki ke hana i ka porosity e like me 0.1–0.3% o ka nui o ka ingot, hoʻopalekana i ka pono mechanical.
Solubility a me ka Phase Equilibria
A hiki, hōʻike ka Fe-N i nā hoʻololi pili i ka wela:
- Kiʻekiʻe-Mahana γ-Austenite Field
Ma luna o kahi kokoke 700 ° C, Hiki i kahi māhele γ-austenite hoʻokahi ke hoʻopaʻa i ka interstitial N. Kokoke loa ka solubility 0.11 wt% a 1 200 °C a me ke kaomi lewa. - ʻO Sub-700 °C Nitride a me ka Evolution Gas
Ke hāʻule ka mahana, Hōʻole ka lattice i ka nui o N. Ma lalo 700 ° C, hiki ke hoʻoheheʻe ʻia ka nitrogen ma ke ʻano he nitrides paʻa (E.g., Aln, Kū) a i ʻole ke kinoea N₂.
I ka lumi lumi, hāʻule ka solubility i < 0.005 wt%, no laila, lilo ka nui o ka hoʻoluʻu akahele a me ka hoʻolālā ʻana i ka alloy no ka puʻunaue pono ʻana iā N. - Nā hopena paʻakikī
Hiki i ka hoʻonui ʻana i ka argon a i ʻole ke kaomi ʻāpana nitrogen ke hoʻololi i ka solubility: a 5 atm N₂ ea hoʻokiʻekiʻe i ka hoʻonā wela kiʻekiʻe a hiki i 15%,
akā ʻo ka hapa nui o ka hana kila e kū kokoke ana 1 atm, e hōʻike ana i ke koʻikoʻi o nā lāʻau lapaʻau e hoʻokuke aku iā N.
Ka launa pū me nā mea hoʻohui
Eia hou, ʻAʻole hana wale ka nitrogen. Hoʻokumu ia i nā pilina paʻakikī e hoʻohuli i ka microstructure a me nā waiwai:
- Nā Nitride-Formers ikaika
Titanium, aluminum, a hoʻopaʻa ka niobium i ka nitrogen e like me TiN, Aln, a i ʻole NbN.
Hoʻopili kēia mau mea i nā palena palaoa a hoʻomaʻemaʻe i ka austenite, e unuhi pololei ana i ka ferrite maikaʻi a i ʻole martensite ma hope o ka hoʻololi ʻana. - Hoʻohui kūpono me Carbon a me Manganese
Hiki ke hui pū ka Nitrogen me ke kalapona e hoʻohua ai i ka Fe₄N a i ʻole me ka manganese e hana ai i Mn₄N..
I nā kila kila haʻahaʻa, ʻO kēia mau nitrides e hoʻopaʻapaʻa ma nā palena palaoa, e ho'ēmi ana i ka paʻakikī inā waiho ʻole ʻia. - ʻO Synergy me Chromium i loko Nā mea kanu lāʻau
Ma nā māka austenitic (E.g., 316, 2205 Duplex), hoʻonui ka nitrogen i ka paʻa o ke kiʻiʻoniʻoni passive.
Kēlā 0.1 Hiki i ka wt% N hoʻohui ke hoʻonui i ka Pitting Resistance Equivalent Number (Wood) ma kahi o 3 Nā'āpana, ka hoʻomaikaʻi ʻana i ka pale ʻana i ka chloride-induced corrosion.
Ke Ana a me ke Anaina
Hope loa, ʻO ka quantification kūpono o ka nitrogen ke kumu o kēlā me kēia hoʻolālā mana. Aia nā ʻenehana nui:
- ʻO ka hui ʻana o ka inert-gas (ʻIkepili LECO)
Hoʻoheheʻe nā mea hoʻohana i kahi hāpana kila i loko o kahi pahu graphite ma lalo o ka helium; hele ka N₂ i hoʻokuʻu ʻia i loko o kahi mea ʻike infrared.
Hāʻawi kēia ʻano hana ± 0.001 wt% pololei a hiki i ka 0.003 wt% huina N. - Lawe Wela Wela ʻO ka lawe ʻana i ke kinoea
Iiiai, hoʻoheheʻe ʻia nā mea hoʻoheheʻe ʻia i loko o ka umu hoʻokuʻu ʻia i hoʻoheheʻe ʻia a hui pū ʻia ka nitrogen.
Ma ka nānā ʻana i ka ulu ʻana o N₂ me ka manawa, Hoʻokaʻawale nā laboratories ma waena o interstitial N, Nitrides, a me nā ʻeke kinoea. - Hoʻohui ʻia ʻo Vacuum Inert-Gas Fusion
E hōʻoia i ka maikaʻi o nā hana degassing, nui nā mea kanu e hoʻohana ana i nā mea hoʻokaʻawale fusion vacuum e hana ana ma lalo 1–10 mbar.
ʻIke kēia mau mea hana i nā loli sub-ppm i ka N, alakaʻi i nā hoʻoponopono kaʻina hana e mālama i nā pae ma lalo o nā paepae i manaʻo ʻia (E.g., ≤ 20 ppm i nā kila maʻemaʻe loa).
3. Nā hopena maikaʻi o ka Nitrogen i ke kila
Hāʻawi ka Nitrogen i nā pōmaikaʻi he nui ke hoʻomalu pono nā ʻenekinia i kāna ʻike.
Ma lalo, ke nānā nei mākou i ʻehā mau pōmaikaʻi koʻikoʻi—kākoʻo ʻia kēlā me kēia me ka ʻikepili quantitative a hoʻopaʻa pū ʻia me nā hoʻololi maopopo e hōʻike i ke ʻano o ka hoʻokiʻekiʻe ʻana o N i ka hana kila..
Hoʻoikaika Paʻa-Solution
Mua a mua loa, hoʻoheheʻe ʻia nā ʻātoma nitrogen i ka hao a keʻakeʻa i ka neʻe ʻana.
Iloko 0.01 wt% o ka interstitial N e hoʻohui maʻamau ≈ 30 Mpa e hāʻawi i ka ikaika.
ʻo kahi laʻana, i loko o kahi kila microalloyed i loaʻa 0.12 wt% C a 0.03 wt% N, piʻi ka ikaika hua mai 650 Mpa e luna 740 MPa—he piʻi o ka ʻoi aku ma mua o 14%—me kahi kūʻai haʻahaʻa wale nō i ka ductility.
Hoʻomaʻemaʻe i ka palaoa ma o ka Nitride Precipitates
Eia hou, hoʻokumu ka nitrogen i nā nitrides ultra-fine (20–100 nm) me nā mea hana nitride ikaika e like me Al a me Ti.
I ka wā hoʻoluʻu hoʻomalu, ʻO kēia mau precipitates pin i nā palena palaoa austenite. NOEHUI, emi mai ka awelika o ka nui o ka hua austenite 100 }m a lalo i 20–30 μm.
Ma ka ʻaoʻao aʻe, ʻO ka microstructure hoʻomaʻemaʻe e hoʻokiʻekiʻe i ka paʻakikī o Charpy-V ma -20 °C a hiki i 15 J, ʻoiai e hoʻomaikaʻi ana i ka elongation like ʻole e 10-12%.
Hoʻonui i ka pale ʻana i ka corrosion
Kahi mea hou aʻe, naikokene bolsters lua a me ka crevice-corrosion kū'ē i nā kuhiliʻole a me duplex kila.
ʻo kahi laʻana, hoʻohui 0.18 wt% N i a 22 Hoʻonui ka papa duplex Cr–5 Ni–3 Mo i kāna Helu Kaulike Pitting Resistance (Wood) ma kahi kokoke 10 Nā'āpana.
Ma ka hopena, ka pitting-corrosion rate o ka mea 3.5 wt% NaCl hāʻule ma kahi kokoke 30%, ka mea e hoʻonui ai i ke ola lawelawe i loko o ke kai a me ka hoʻoheheʻe kemika.
Hoʻomaikaʻi i ka luhi a me ka hana kolo
Hope loa, ma lalo o ka cyclic loading, hōʻike nā kila hoʻoikaika kino nitrogen a 20-25% ʻoi aku ka lōʻihi o ke ola luhi ma nā amplitudes koʻikoʻi ma luna 400 Mpa.
Pela paha, i na hoao kolo ma 600 ° C a 150 Mpa, nā kila i loaʻa 0.02–0.03 wt% N Hōʻikeʻia a 10-15% haʻahaʻa haʻahaʻa creep rate hoʻohālikelike i ko lākou mau hoa haʻahaʻa-N.
Loaʻa kēia hoʻomaikaʻi ʻana mai ka hiki ʻana o nā pūnaewele nitride ke pale aku i ka hoʻoheheʻe ʻana i ka palena o ka palaoa a me ka hoʻomaka ʻole..
Pākaukau 1: Nā hopena maikaʻi o ka Nitrogen i ke kila
| Hopena | Mea lihua | Kūlana N maʻamau | Ka hopena nui |
|---|---|---|---|
| Hoʻoikaika Paʻa-Solution | Hoʻololi ka Interstitial N i ka lattice, keʻakeʻa i nā dislocations | +0.01 wt% no ka hoʻonui | +≈ 30 MPa ikaika hua no 0.01 wt% N |
| ʻO ka lepo lepo | Nano-nitride (AlN/TiN) precipitates pin austenite palena | 0.02–0.03 wt% | Ka nui o ka palaoa ↓ mai ~100 μm a 20-30 μm; Ka hopena Charpy ↑ a hiki i 15 J ma –20 °C |
| Ke kū'ē neiʻo Corrosionion | N hoʻopaʻa i ke kiʻiʻoniʻoni passive, hāpai PREN | 0.10–0.20 wt% | Wood +10 Nā'āpana; pitting rate in 3.5 wt% NaCl ↓ na ≈ 30 % |
| Kaluhi & Hoʻokō Creep | Hoʻopilikia nā pūnaewele Nitride i ka hoʻoheheʻe ʻana o ka palena a me ka ulu ʻole | 0.02–0.03 wt% | Ola luhi +20–25 % ma ≥ 400 Mpa; ka helu kolo ↓ 10–15 % a 600 ° C, 150 Mpa |
4. Nā hopena pōʻino o ka Nitrogen i ke kila
ʻOiai ke lawe mai nei ka nitrogen i nā pōmaikaʻi, ʻO kona keu ke alakaʻi i ka hana koʻikoʻi a me nā pilikia hoʻoponopono.
Ma lalo, kikoʻī mākou i ʻehā mau drawbacks nui-ʻo kēlā me kēia i kuhikuhi ʻia e ka ʻikepili nui a hoʻopili ʻia me nā hoʻololi e hōʻike i ke kumu a me ka hopena..
lumi-Mamahana Aging Embrittlement (“Blue Brittleness”)
Akā naʻe,, na kila i oi aku mamua o 0.02 wt% N ʻeha pinepine i ka embrittlement ke mālama ʻia ma 200-400 ° C.
Ma luna o ʻeono mahina, nā pūnaewele nitride koʻikoʻi (E.g., Fe₄N a me Mn₄N) hana ma na palena palaoa.
Ma ka hopena, Hiki ke hāʻule ka paʻakikī o Charpy-V 50% (ʻo kahi laʻana, Mai 80 J iho i 35 J at 25 ° C), e hoʻohaʻahaʻa i ka ductility a me ka pilikia i ka hana ʻana i ka hana ʻana i nā hao hao haʻahaʻa.
ʻO ka Embrittlement Kūlana Kiʻekiʻe a me ka Nalo ʻana o ka Hot-Ductility
Eia hou, i ka wā hoʻolili mālie 900-1000 ° C, Nb-kaui kila (0.03 Nb–0.02 C–0.02 N) hoʻokahe maikaʻi (Nb, C)N nā ʻāpana i loko o nā hua austenite kahiko.
NOEHUI, tensile elongation hāʻule loa—mai 40% i lalo 10%- ka hoʻohālikelike ʻana i ka hana ʻana i ka wā o ka forging a i ʻole ka ʻōwili ʻana.
Nui loa, Ma lalo 900 ° C, Hana ʻia ʻo AlN ma nā palena ʻai, e hoʻonui ana i ka haʻihaʻi intergranular a me ka hoʻopaʻa ʻana i ka hana wela i nā kila kila kiʻekiʻe a i ʻole microalloyed..
ʻO ke kinoea a me ka hoʻolei ʻana i nā hemahema
Kahi mea hou aʻe, nā kila hoʻoheheʻe me ka N i hoʻoheheʻe ʻia ma luna 0.015 wt% hiki ke hoʻopau i ka N₂ i ka wā paʻa, e hana ana i ka porosity e noho ana a hiki i 0.3% o ka leo ingot.
Ke hana nei kēia mau micro-blowhole ma ke ʻano he koʻikoʻi koʻikoʻi: hōʻike nā hōʻike luhi a 60% hoemi i ke ola ma lalo o ka cyclic bending.
Pela paha, E hāʻule paha ka ikaika tensile static 5-10% i nā ʻāpana ʻoi aku ka mānoanoa ma mua o 100 mm, kahi e hōʻiliʻili nui ai ke kinoea paʻa.
Nā Pilikia Weldability: Hoʻokomo ʻia ʻo Wela a me Nitride
Hope loa, i ka wā hoʻoheheʻe arc, Hoʻokuʻu nā pōʻai wela wikiwiki i ka N i hoʻoheheʻe ʻia ma ke ʻano he ʻehu kinoea a hoʻoulu i nā nitride hoʻoheheʻe kiʻekiʻe i loko o ka hui ʻana a me nā ʻāpana wela..
NOEHUI, piʻi ka naʻau wela ma ka 20-30%, ʻoiai hiki ke emi iho ka paʻakikī o ka weld-metal 25% (E.g., Mai 70 J keia 52 J ma –20 °C).
ʻO ia mau hemahema e hoʻoikaika pinepine i ka mālama wela ma hope o ka weld a i ʻole nā mea hoʻohana kūikawā, hoʻohui i ke kumukūʻai a me ka paʻakikī i ka hana ʻana.
Pākaukau 2: Nā hopena pōʻino o ka Nitrogen i ke kila
| Hopena | Mea lihua | Paepae N pae | Ka hopena nui |
|---|---|---|---|
| lumi-Mamahana Aging Embrittlement ("Polū") | Hana ʻia ʻo Fe₄N/Mn₄N ma nā palena i ka wā ʻelemakule 200–400 °C. | > 0.02 wt% | ʻO ka paʻakikī Charpy ↓ > 50 % (E.g., Mai 80 J keia 35 J at 25 ° C) |
| Embrittlement Kūlana Kiʻekiʻe & Pohō-Hoʻohuʻi Wela | (Nb,C)ʻO N a me AlN e kahe ana i ka wā 900–1 000 °C hoʻolili mālie | ≥ 0.02 wt% | Elongation ↓ mai 40 % i < 10 %; poho formability nui |
| ʻO ka pololi & Hōʻalo ka mea hana hewa | ʻO nā ʻōhū N₂ keu i hana i ka porosity i ka wā paʻa | > 0.015 wt% | Porosity a hiki i 0.3 % Volume; ola luhi ↓ ≈ 60 %; ikaika tensile ↓ 5–10 % |
| Nā Pilikia Weldability | N₂ evolution a me nitride inclusions in fusion/HAZ zones | ≥ 0.01 wt% | ʻO ka ʻike wela +20-30 %; weld-metala paʻakikī ↓ 25 % (70 J → 52 J ma –20 °C) |
5. Nā Kuleana no ka Mana Pono Nitrogen
Ka hana kila mua
E hoʻomaka, Kamaoaf a Bof hoʻohana i ka inert-gas stirring (ARHERE AR, Poliuawaena co₂) ma ka uku oi aku 100 Nm³/min, e hoʻokō ana i ka 60% N ka wehe ʻana i kēlā me kēia pōʻai.
Metallurgy Secondary
Mahope iho, hoʻomāmā (VD/VOD) malalo < 50 mbar hoʻopau ke kaomi a hiki i 90% o ke koena N, ʻoiai ʻo ka hoʻomaʻemaʻe argon wale nō e wehe 40-50%.
Huli nā mea kanu ≤ 0.008 wt% Hoʻonohonoho pinepine ʻo N i ʻelua a ʻoi aku paha VD pass.
Nā ʻenehana hoʻoheheʻe
Kahi mea hou aʻe, ESR a ʻO kā mākou ʻaʻole wale e hoʻomaʻemaʻe i ka hoʻomaʻemaʻe hoʻohui ʻia akā e hoʻemi pū i ka N e 0.005 wt% pili i nā ingots maʻamau ma muli o ka wela nui a me ke kaomi haʻahaʻa.
Nā hana hao maʻemaʻe
Hope loa, ʻO ka hōʻemi ʻana i ka ʻike ʻana i ka lewa i ka wā e ninini ana i nā tudles i hoʻopaʻa ʻia a me nā uhi argon e pale ai i ka hoʻopili hou ʻana o N., kōkua i ka mālama ʻana i ka N ma lalo 20 ppm i nā māka ultra-maʻemaʻe.
6. Hana Hana Hana
| Noi | Hoʻolālā | N Papa | Loaʻa ka nui |
|---|---|---|---|
| 9Cr–3W–3Co Ultra-haʻahaʻa-N ʻilikai | Kamaoaf + multi-pae VD + ESR | ≤ 0.010 wt% (100 ppm) | +12 ʻO J Charpy ʻoʻoleʻa ma –40 °C |
| HiB Transformer Silicon Steel | Ka manawa paʻa & Kauhane (± 5 S) | 65–85 ppm | –5% poho kumu; +8% hiki ke hoʻopalekana |
| 1 100 MPa Welding-Wire Steel | Alloy-tuning + kaʻina hana hoʻoponopono | 0.006–0.010 wt% | Tersele > 1 100 Mpa; elongation ≥ 12% |
| 5 N-Grade Ultrapure hao | Electrolysis → hoʻoheheʻe ʻana i ka ʻūhā → VZM | Huina kinoea ~ 4.5 ppm | Semiconduc pā & maʻemaʻe magnetic-grade |
7. Nitriding
Ma waho aʻe o ka mana nui N, nitriding ili hana i ka paakiki kūloko.
Aila, plasma, a i ʻole ʻauʻau ʻauʻau nitriding e hoʻokomo i 0.5 wt% N i loko o a 0.1–0.3 mm papa hoʻopuehu, hooikaika ana i ka paakiki ili mai ~200 HV i 800-1 000 Him.
Eia nō naʻe, hiki ke hana i ka ε-Fe₂₋₃N "nā papa keʻokeʻo" i pohā ma lalo o ka luhi., no laila ka hoʻomaʻamaʻa post-nitriding (≈ 500 ° C no 2 huh) e hahai pinepine i ka hoʻopaʻapaʻa.
8. Nā hopena
Hana maoli ʻo Nitrogen ma ke ʻano he "lima maka pālua" i ka metallurgy kila.
Ke mālama ʻia i loko o nā puka makani paʻa (maʻamau 0.005–0.03 wt%), hāʻawi ʻo ia i ka hoʻoikaika paʻa, ʻO ka lepo lepo, a me ka loaʻa ʻana o ka corrosion-resistant.
Like, ʻoi aku ka nui o N hoʻoulu i ka embrittlement, Potiwale, a me nā pilikia wili.
No laila, ʻO ka hana kila o kēia manawa ke hoʻohana nei i ka degassing kiʻekiʻe, hoohehee hou ana, a me nā hoʻolālā kila maʻemaʻe-me ka nānā ʻana i ka manawa maoli-e hoʻopaʻa i ka nitrogen i kona pae pono loa..
Ke ulu nei nā kila i ka hana kiʻekiʻe a me ka hoʻomau, ʻO ka haku ʻana i ke ʻano ʻelua o ka nitrogen he mākaukau koʻikoʻi no nā metallurgists a me nā ʻenekini hana like.
ʻO kēia ʻo ia ke koho kūpono no kāu mau pono hana inā pono ʻoe kila kila kiʻekiʻe.
FaqS
Hiki i ka nitrogen ke hoʻomaikaʻi i ka pale ʻana i ka corrosion i nā kila kila?
ʻAe. ʻo kahi laʻana, hoʻohui 0.18 wt% N i ka papa duplex (22 Cr–5 Ni–3 Mo) hoʻāla
kona PREN e ≈ 10 ʻāpana a hoʻemi i ka pitting rates in 3.5 wt% NaCl ma kahi o 30%, ka hoʻonuiʻana i ke ola lawelawe i nā wahi kūwaho.
He aha nā ʻano analytical analytical quantify nitrogen in steel?
- Hoʻohui kinoea (Leoc): ± 0.001 wt% pololei no ka huina N.
- ʻO ka lawe ʻana i ka wela wela: Hoʻokaʻawale ʻia, paʻa i ka nitride, a me ke kinoea N₂ no ka kikoʻī kikoʻī.
- Hoʻohui ʻia i ka ʻumeke: Hana ʻia ma lalo o 1-10 mbar e ʻike i nā loli sub-ppm ma hope o ka degassing.
Pehea ka ʻokoʻa ʻana o ka nitriding me ka hoʻokele nitrogen bulk?
Huli ka mana nui o N ma ka 0.005–0.03 wt% no nā waiwai o loko.
He ʻokoʻa, nitriding ili (aila, plasma, ʻauʻau paʻakai) laha a hiki i 0.5 wt% N i loko o kahi papa 0.1-0.3 mm,
hoʻonui i ka paʻakikī o ka ʻili (200 HV → 800–1 000 Him) akā e koi ana i ka hoʻomaʻamaʻa post-nitriding e pale i nā papa keʻokeʻo brittle.
Hoʻohana ka poʻe hana kila i ka hoʻoheheʻe ʻana i ka pahu pahu (ʻO kā mākou) a i ʻole electroslag remelting (ESR) e hoʻokuʻu i ka N ma lalo o nā wela kiʻekiʻe a me nā haʻahaʻa haʻahaʻa.
KAHUIA, ʻO nā kīʻaha i hoʻopaʻa ʻia a me nā argon pale a i ʻole nā puʻi nitrogen i ka wā o ka paʻi ʻana e pale iā N reabsorption, e hoemi ana i ka porosity i < 0.1%.
