No ke aha e pale ai ka hao i ka ʻino ma mua o ke kila kalapona?

1. ʻO ka hōʻuluʻuluʻana

ʻOi aku ka maikaʻi o ka hao hao ma mua o ke kila kalapona maʻamau i nā wahi ʻino maʻamau ma muli o kāna kemika a me ka microstructure e hana i kahi ka hopena pale ʻelua: ʻO nā hana graphite inert e hoʻemi i ka wahi metala hana electrochemically, ʻoiai ʻo ke silikoni i loko o ka matrix e hana i kahi kiʻiʻoniʻoni ʻili nui i ka silica e hoʻopaʻa a hoʻopaʻa i ka unahi corrosion..

ʻO kēia mau hopena ʻelua e hoʻolōʻihi i ka oxygen a me ka lawe ʻana i ka ion i ka metala kumu a hoʻemi i ka nui o ka corrosion ma nā wahi kūʻokoʻa a me ka haʻahaʻa haʻahaʻa..

ʻO ka pōmaikaʻi e pili ana i ka pōʻaiapili: i ka ʻakika loa, hoemi ikaika, a i ʻole nā ​​mea hoʻoheheʻe kalapona kūpaʻa i ka pāpaʻi chloride (E.g., nā mea kanu lāʻau, Duplex) ʻoi aku ka maikaʻi o nā mea laina.

2. Pane pōkole

Hae haoʻoi aku ka maikaʻi o ka hana corrosion i hoʻohālikelike ʻia me ʻaihue kīwī ʻo ka mea nui microstructural a me kemika - hāʻawi ka graphite i kahi kino, pale i hāʻawi ʻia, a hoʻokumu ke silika i kahi kiʻiʻoniʻoni waiwai SiO₂ paʻa e hoʻopaʻa a hoʻopaʻa i ka unahi hao-oxide porous..

ʻO kēia mau hana ʻelua e hoʻolōʻihi i ka electrochemical oxidation o ka hao ma lalo o nā kūlana lawelawe.

3. Hoʻokumu metallurgical - haku mele a me nā ʻokoʻa microstructure

Nā haku mele maʻamau (nā pae ʻelele)

Pohō: ʻOi aku ka nui o ke kalapona a ʻoi aku ka nui o ke kalapona ma ka hao hao ma mua o ke kila kalapona.
Stucial, i loko o ka hao hao nui ka carbon i loaʻa e like me mooki Nā Haka; i ke kalapona kila ua paʻa kemika i loko o ka hao matrix (Ferrite / Mipite) a i ʻole e like me ka cementite.

ʻokoʻa microstructural

Hae hao

nā nodule graphite a i ʻole nā ​​ʻōpala i hoʻokomo ʻia i loko o kahi matrix hao (Ferrite / Mipite). ʻO ka graphite he mea kemika a me ka uila; kona morphology (flake vs spheroid) pili pū kekahi i ka hana mechanical a me ka corrosion.

ʻAihue kīwī (HE MOOLELO LOT' / ʻO kaʻaihueʻoluʻolu)

• Moloka: nui loa ferrite + Puʻuʻupuʻu (ferrite = palupalu, ductile α-Fe; pearlite = lamellar Fe + Likahi).
• Wahi kalapona: hoʻoheheʻe ʻia i loko o ka ferrite i nā mea liʻiliʻi a hoʻopaʻa ʻia i loko simentite (Likahi) lamellae i ka pearlite.
  The metallic surface is essentially continuous iron; there is no inert dispersed carbon phase.
• Typical consequences: homogeneous metallic surface with uniform electrochemical activity; rapid macroscopic oxidation if unprotected.

4. Ka pale corrosion pālua i ka hao hao - pale graphite a me ka silica (Sio₂) hoʻolauna

Cast iron’s superior resistance to many forms of corrosion arises from two complementary mechanisms that operate at the microstructural level: (1) a physical barrier effect from the graphite phase, a (2) a Keena Kokua provided by silica (Sio₂) hoʻokumu.
Together these mechanisms slow the electrochemical processes that drive metal loss and extend service life in many outdoor and aqueous environments.

Graphite — he kino, pale micro-scale

• Chemical stability and inertness. Graphite is a chemically inert allotrope of carbon.
  It does not oxidize readily under common environmental conditions (Kōlea, kaiwa), no laila, ʻaʻole hana nā ʻāpana graphite i hoʻokomo ʻia i loko o ka matrix metala ma ke ʻano he wahi anodic a ʻaʻole kōkua i ka corrosion ikaika..
• Palena micro-scale. I loko o nā hao hao, ʻike ʻia ka graphite e like me nā flakes (hao hina) a i ʻole nā ​​spheroids (Ui).
  Hoʻokaʻawale ʻia kēia mau hiʻohiʻona graphite ma ka ʻili a me lalo a hana e like me nā pale microscopic hiki ʻole ke helu ʻia e hōʻemi i ka wahi i ʻike ʻia o ka matrix hao reactive..
  Ma ka hoʻopau ʻana i ka pilina pololei ma waena o ka hao a me nā ʻano mea ʻino (oxycongen, wai, nā iona chloride), ʻo ka graphite phase e hōʻemi ana i ka wahi electrochemical kūpono i loaʻa no ka hoʻohemo ʻana.
• Ka hopena ʻupena vs. ʻaihue kīwī. Loaʻa i nā kila kalapona kēia i loko, mahele inert māhele; ʻike nui ʻia ka matrix hao ma nā kila kalapona, no laila e hoʻouka like ʻia ka hoʻouka ʻana o ka oxidative ma luna o ka ʻili metala.

Silicon — ka hoʻoheheʻe kemika ma o ka hana kiʻiʻoniʻoni SiO₂

• Ke kumu electrochemical. ʻO ka ʻino ʻana o ka hao kahi kaʻina hana hoʻokahe electrochemical kahi e nalowale ai nā ʻātoma Fe i nā electrons a hoʻokumu i nā ʻano ʻokikene.
  ʻO ka loaʻa ʻana o ke silikoni i loko o ka hao hoʻoheheʻe e hoʻololi i nā ala kemika i ka wā o kēia oxidation.
• ʻO ka oxidation makemake a me ka hana kiʻiʻoniʻoni. Hoʻopili ʻia ka silikoni me ka ʻaoʻao-a i kekahi mau hihia ma mua o ka hao e hana ai i kahi paʻa, silika pili (Sio₂) kiʻiʻoniʻoni ma ka ʻili metala.
  Hoʻopiha kēia papa silica i nā pores a me nā hemahema i loko o ka hao-oxide mua ('ōwili) papa a hoʻopaʻa maikaʻi i ka substrate.
• Nā waiwai pale o SiO₂. ʻO ke kiʻiʻoniʻoni SiO₂ paʻa a paʻa kemika; e hoemi ana i ka hoolaha ana o ka oxygen a me na iona ikaika iloko o ka metala a pela e hooloihi ai i ka oxidation o ka hao..
  I ka wehe ʻana i waho, ʻO ka unahi pale ma luna o ka hao hoʻoheheʻe pinepine ʻia he kiʻiʻoniʻoni hui ʻia o ka hao oxides a me ka silica; hoʻomaikaʻi ka ʻāpana silica i ka hui ʻana a hoʻemi i ka ʻili ʻana o ka papa ʻōpala.
• Hoʻohālikelike me ka ʻeleʻele kila kalapona. ʻO ka ʻōpala ma luna o ke kila kalapona ka mea maʻamau i haku ʻia me nā ʻohe hao porous (FeO, Lihuaipuai, Lihuaipuai) i nele i ka paakiki, ka hoʻopili ʻana o nā kiʻiʻoniʻoni waiwai silica.
  ʻO ka'ōpala carbon-steel e maʻalahi, porous a ino ka paa, no laila e paheʻe a hōʻike i ka metala hou - e hana i ka holomua, hoʻokē ʻino.

Pehea e hana like ai nā mīkini ʻelua

• Synergy. Hoʻemi ʻo Graphite i ka ʻāpana ili hao ikaika i loaʻa no ka ʻino, ʻoiai e hana ana ke kiʻiʻoniʻoni silica i kahi e ʻino ai ka hao - hoʻopaʻa a hoʻolohi i ka hoʻouka uila.
  ʻO ka hopena i hui pū ʻia, ʻoi aku ka liʻiliʻi o ka corrosion rate a me ka hoʻokumu ʻana i kahi unahi ʻoi aʻe o ka ʻili ma mua o ka hana ʻana ma ke kila kalapona..
• Ka hopena kūpono. I loko o ka nui o ka lewa a me ka hoʻomāinoino ʻole i ka wai, hoʻomohala ka hao i hale paʻa, ʻO ka papa pale paʻa e hoʻopaneʻe i ke komo hohonu a me ka nalowale o ke kino.
  ʻO kēia ke kumu e hiki ai i nā mea hao hao ke hōʻike i nā ola lawelawe lōʻihi ma ke kaona, hale kūkulu hale a me nā noi ʻoihana he nui inā ʻaʻole i lalo i nā kemika koʻikoʻi.

Nā palena a me nā noʻonoʻo pono

• Pili kaiapuni. ʻO ke kiʻiʻoniʻoni pale waiwai nui ka silica ma ke kūʻokoʻa a hiki i nā kaiapuni haʻahaʻa.
  I nā kūlana acidic ikaika, mea hoʻomake nui loa, a i ʻole i ka hoʻopaʻa ʻia ʻana i loko o nā hāʻina chloride ikaika, ua ho'emi 'ia nā pōmaika'i pasif a hiki ke ho'omau 'ia ka 'ino.
• Nā pūnaewele galvanic kūloko. ʻO ka graphite ka uila; inā e hoʻopili ʻia nā wahi i ʻike ʻia o ka graphite i kahi electrolyte conductive a loaʻa kahi metala anodic, hiki i nā pilina galvanic kūloko. Pono ka hoʻolālā e pale i ka pilikia galvanic i nā hui metala nui.
• Kūlana ʻili a me nā uhi. Nā uhi pale, ʻO nā linings a i ʻole ka pale cathodic e koi pinepine ʻia i ka wā e pono ai ka hao hao ke pale aku i nā kemika koʻikoʻi, hoʻopaneʻe lōʻihi, a i ʻole ke koi ʻia nā koi hoʻoponopono i ka leaching kokoke-zero (E.g., Nā'ōnaehana wai hui).
  Kōkua pū nā uhi i ka mālama ʻana i ka pālākiō waiwai ʻo SiO₂ i ka wā lawelawe mua.
• Mana hana. pae silika, haku mele, graphite morphology a me ka hoʻolei ʻana i ka pololei (Potiwale, Nā Hoʻohui) pili nā mea a pau i ka pono o ka pale pālua.
  ʻO ka hoʻomaʻamaʻa ʻana maikaʻi a me nā kikoʻī kūpono o ka kemika a me ka microstructure he mea nui.

5. Electrochemical a me ka corrosion-mechanism kuanaʻike

ʻĀpana hana a me nā kinetics

• ʻAiʻi ʻana o kēia manawa pili i ka wahi hana electrochemically. I ka hao hao, ua hoemi ia ka wahi hao ikaika o ka ili i ikeia e ka uhi graphite — e hoemi ana i ke au anodic a me ka huina poho metala ma lalo o na kaiapuni like..
• Ke kū'ē kū'ē pālākiō: ʻOi aku ka paʻa, ʻO ka pālākiō waiwai nui ka silica e hoʻonui i ke kūʻē i ka ionic a me ka molecular diffusion (OAHO, Hue, Cl⁻), hoʻohaʻahaʻa maikaʻi i nā pākēneka pane.

Nā noʻonoʻo pīhoihoi Galmanni (he hoʻomanaʻo)

• graphite conductivity: ʻO ka graphite ka uila.
  Ke hōʻike ʻia ka graphite ma ka ʻili a loaʻa kahi electrolyte conductive, Hiki ke hoʻokumu ʻia nā cell galvanic kūloko kahi e hana ai ka graphite ma ke ʻano he kahua cathodic a lilo ka hao kokoke i anodic.. Ma kekahi mau geometries keia hiki hoʻopuka i ka ʻinoʻino kūloko.
• Koena ʻupena: I nā kūlana kūpono, ʻoi aku ka nui o ke kiʻiʻoniʻoni pale a me ka wahi hana i hoʻemi ʻia ma mua o ka pilikia galvanic kūloko, akā, pono e pale ka hoʻolālā i nā hoʻonohonoho ʻana kahi e hana ai ka graphite i nā ʻāpana cathodic kiʻekiʻe i hui pū ʻia me nā metala maikaʻi ʻole..

6. Hana ai.uk, ka hana a me nā mea lawelawe e pili ana i ka hana corrosion

• pae silika: Kiʻekiʻe Si (i loko o nā palena hoʻokumu) hoʻoikaika i ka hoʻokumu ʻana o SiO₂ ikaika; hao-hao maʻamau Si ≈ 1–3 wt% versus carbon steel ≈ 0.1–0.5 wt%.
• ʻO ka graphite morphology a me ka puʻunaue: Ui (ʻO ka kiʻi) a me ka hao hina (graphite liʻiliʻi) ʻokoʻa i ke ʻano o ka hui ʻana o ka pae graphite i ka ʻili; he uku, Hāʻawi maikaʻi ka māhele graphite i ka pale like ʻole.
• Kūlana ʻili a me ka unahi: Mill/wela lapaʻau, fusion coatings, a e pili ana ka ʻino kūlohelohe i ka wikiwiki o ka ulu ʻana o ka unahi silica/oxide pono.
  Hiki ke ʻino nā ʻili i hana ʻia a hiki i ka puka ʻana o ka unahi paʻa.
• ʻO ka maʻemaʻe a me ka porosity: Nā Hoʻohui, Hiki i nā blowhole a i ʻole ka hoʻokaʻawale ʻana ke lilo i wahi hoʻomaka no ka hoʻouka kūloko. ʻO ka hana hoʻoheheʻe maikaʻi e hōʻemi i kēia mau pilikia.
• Nā pāpale & loli nā loulou: Loaʻa pinepine ka hao i nā uhi (epoxy, puna sima, ʻO ka lining) e hoʻomaikaʻi hou aʻe i ke ola corrosion i loko o nā wahi ʻino.

7. Pili kaiapuni a me ke kūlana lawelawe

ʻOi aku ka maikaʻi o ka hao hao ma mua o ke kila kalapona

• Hōʻike lewa (kaona / kuaaina)—ʻo ka ʻāpana silica e hoʻomaikaʻi i ka pili ʻana o ka patina a hoʻolōʻihi i ka nalowale holomua.
• ʻO ka wai inu a me ka wai ʻino—i ka wā i laina ʻia/i uhi ʻia a i ʻole i loko o nā pae pH paʻa, ʻoi aku ka lōʻihi o nā paipu hao i hoʻolei ʻia a me nā mea pono.
• ʻO nā kaiapuni wai hoʻokahe kūpono—Pomaikai ka unahi waiwai silica.

Kaiapuni kahi i hao ai ʻaʻole luna loa

• Mea hoʻopaʻapaʻa ʻakika loa (pH haʻahaʻa) - hiki ke hoʻouka a hoʻoheheʻe ʻia ke kiʻi silica; hikiwawe loa ka hao nui.
• Kaiapuni chloride ikaika (Ke wai wai, Heni) - hiki i ka hoʻouka ʻana a me ka lua ʻana ke hōʻino i ke kiʻi pale; ʻoi aku ka maikaʻi o nā alloys stainless a duplex paha.
• Ka hoʻohiheʻana, nā ʻāina a i ʻole nā ​​wai waiwai sulfide - ka ʻino ʻana i ka microbiologically (Mic) a hiki i nā ʻano sulfide ke hoʻouka ikaika i ka hao.

8. ʻO ke kālepa koho waiwai

no ke aha ʻaʻole i hoʻohui nui ʻia ke kila a no ke aha i koho ʻia ai ka hao hao

ʻO ka hoʻohui ʻana i nā kiʻekiʻe kiʻekiʻe o ka silika i ke kila e hoʻonui i kona kūʻē ʻana i ka oxidation a hiki ke hoʻoikaika i ka hoʻokumu ʻana i nā kiʻiʻoniʻoni pale waiwai silica., akā, hoʻokiʻekiʻe hoʻi ia i ka palupalu o ka alloy.

No ka nui o ka hoʻohana ʻana i nā mea kila—ma kahi o ka plasticity kiʻekiʻe, ʻO ka paʻakikī a me ka hiki ke hoʻopaʻa pono ʻia - ʻaʻole ʻae ʻia ka embrittlement i hana ʻia e ka ʻike silika kiʻekiʻe..

Ma ka hopena, ʻO nā kila kalapona koʻikoʻi e mālama haʻahaʻa i ka silika a hilinaʻi i nā ala ʻē aʻe (Nā pāpale, mea hoʻopaneʻe, hui pū me Mn/Cr/Mo, a i ʻole ka hoʻohana ʻana i nā mea hoʻoheheʻe stainless) e hoʻokō i ka corrosion a i ʻole nā ​​koi oxidation.

Hae hao, Ma ka hoʻohālikelike, he kuʻikahi like ʻole. ʻAe ʻo Foundry metallurgy i ka emi ʻana o ka ductility i ke kūʻai ʻana i nā pono i hoʻoholo pinepine ʻia i nā noi kikoʻī.:

• ʻO ka Castability maikaʻi loa. ʻO ke kalapona kiʻekiʻe, hoʻoheheʻe kiʻekiʻe-silikona hoʻohua i nā ʻāpana graphite a me ka hoʻoheheʻe wai e hoʻopiha ai i nā mole paʻakikī, hiki i nā ʻano ʻupena kokoke a me nā hiʻohiʻona i hoʻohui ʻia (nā iwi'ōpala, Nā Wawa, Nā Passing kūloko) paʻakikī a kūʻai ʻia paha ma ka hana ʻana.
• ʻO ka ʻinoʻino a me ka hana ʻaʻahu. ʻO ka microstructure o ka hao hao (mooki + iron matrix me ke silika hoʻokiʻekiʻe) Hāʻawi ka hui pū ʻana o nā ʻano hiʻohiʻona o ka ʻili - ka uhi graphite a me ka hoʻokumu ʻana o ka silica-rich scale - e hoʻolōʻihi pinepine i ka ʻinoʻino a hoʻomaikaʻi i ka pale ʻana i ka ʻaʻahu i nā lawelawe kūʻokoʻa a ʻoluʻolu paha..
• ʻOi aku ka paʻakikī e like me ka hoʻolei ʻana a me ka pale ʻana i ka abrasion. Hāʻawi ka nui o nā māka hao hao i ka paʻakikī o ka ʻili a ʻoi aku ka maikaʻi o ke ola ʻana no nā ʻāpana i ʻike ʻia i nā ʻāpana abrasive (laʻana nā volute pump, nā hale impeller a me nā ʻāpana slurry-handling).
• ʻO ke kumukūʻai a me ka hana ʻana no nā ʻano paʻakikī. No ke geometry paʻakikī ma nā puke liʻiliʻi a me ka liʻiliʻi, hāʻawi pinepine ka hao i ke kumu kūʻai haʻahaʻa haʻahaʻa ma mua o nā hui kila welded a mīkini.

I ka pōkole: pale nā ​​kila kila kiʻekiʻe no ka mea, ʻoi aku ka koʻikoʻi o ka paʻakikī a me ka ductility no ke kūkulu ʻana, nā hui welded;

ʻae ka hao i ka liʻiliʻi liʻiliʻi no ka loaʻa ʻana o ka castability kiʻekiʻe, ʻaʻahu i ka hana a me ke ʻano o ka pale ʻana i ka corrosion intrinsic-e lilo ia i mea koho maikaʻi loa no nā hale pahū he nui., nā kino valve a me nā mea hoʻolei ʻē aʻe e lawelawe ana i ka pāpaʻi abrasive a wai paha.

Hoʻohālikelike mea ʻelele

Nānā: ʻO nā waiwai nā pae ʻenekinia maʻamau no nā ʻano huahana maʻamau (as-cast for ductile hao, maʻamau / ʻōwili ʻia no ke kila kalapona).

Pili nā waiwai maoli i ka papa, ʻO ka mālama wela, ka nui o ka ʻāpana a me ka hana hoʻolako. E hōʻoia mau me nā palapala hōʻoia waiwai a me ka hoʻāʻo kikoʻī noiʻi.

9. Nā hopena

ʻOi aku ka pale ʻana o ka hao hao ma mua o ke kila kalapona no ka mea ua hāʻawi ʻia kāna metallurgy i ʻelua mau mea pale intrinsic.:

He hoopuehu, kemika inert graphite pae e hoemi i ka electrochemically hana ili hao, a me kahi maʻiʻo kiʻekiʻe kiʻekiʻe e paipai ana i ka hoʻokumu ʻana i kahi ʻano paʻa, kiʻi kiʻiʻoniʻoni waiwai silica, ʻo ia ka mea e hoʻopaʻa ai i ka unahi corrosion a hoʻolōʻihi i ka hoʻoneʻe ʻana.

ʻO kēia mau hiʻohiʻona e hana maikaʻi loa i ka hao hao i nā kaiapuni kūʻokoʻa a i ʻole ka haʻahaʻa haʻahaʻa, ʻoi aku ma kahi o nā geometric cast complex, E kāʻei i ke kū'ē, a he mea nui ka pono o ka uku.

 

FaqS

ʻAʻole ʻeleʻele ka hao e like me ke kila?

ʻAʻole. E ʻino mau ka hao, akā, ʻoi aku ka mālie ma nā wahi he nui ma muli o ka pale graphite a me ka pālākiō waiwai nui. Ma lalo o nā kūlana koʻikoʻi hiki ke corrode e like me ke kila.

ʻOi aku ka maikaʻi o ka hao ductile ma mua o ka hao hina no ka ʻino?

Loaʻa nā pōmaikaʻi ʻelua mai ke kiʻi silica; Hāʻawi maʻamau ka graphite spheroidal ductile iron i ʻoi aku ka like o ka hana mechanical a me ka corrosion ma mua o ka flake graphite i ka hao hina..

E hōʻole paha nā uhi i ka pono graphite/Silica?

Nā pāpale (epoxy, Kauwili, ka lole sima) hoʻohui i ka pale a hoʻohana mau ʻia - hoʻokō lākou i nā pono intrinsic.

Akā naʻe,, inā hāʻule ka uhi ʻana, ʻO nā mīkini substrate he mea nui no ke koena o ke ola.

Hiki i ka graphite ke kumu i ka ʻino galvanic?

He conductive ka graphite i hōʻike ʻia a hiki ke hana cathodically; i kekahi mau hui metala a me nā geometries hiki ke hoʻonui i ka hoʻouka kūloko. Hoʻolālā e pale i ka hoʻopili galvanic a hoʻokaʻawale paha i nā pilina.

Pono mau ka uhi ma ka hao?

ʻAe pinepine. Nā uhi a i ʻole nā ​​linings (epoxy, puna sima, Kauwili, Fbe) hoʻokō i ka hoʻomalu kino, pale i ka hoʻouka ʻana i ka wahi mua, a he mea maʻamau no ka wai inu, nā wai hoʻomāinoino a i ʻole lawelawe kanu ʻia.