Corrosion Resistance ntawm Monel K500 rau cov kua qaub muaj zog xws li Hydrochloric Acid thiab Sulfuric Acid
1. Corrosion Resistance rau Hydrochloric Acid
Dilute hydrochloric acid (concentration Tsawg dua lossis sib npaug li 5%) ntawm chav sov: Thaum tsis muaj huab cua lossis oxidizing cov neeg ua haujlwm, Monel K500 qhia tau tias tsis muaj corrosion (tsawg dua lossis sib npaug li 0.1 hli / xyoo) thiab zoo corrosion kuj. Cov khoom tooj liab nyob rau hauv cov hlau ua ib daim nyias nyias, ntom tooj liab chloride zaj duab xis rau ntawm qhov chaw, uas tuaj yeem cuam tshuam ntxiv corrosion ntawm matrix. Txawm li cas los xij, yog tias cov tshuaj aerated los yog muaj oxidizing ions (xws li Fe³⁺, Cu²⁺), cov zaj duab xis passivation yuav raug rhuav tshem, thiab tus nqi corrosion yuav nce ntxiv.
Concentrated hydrochloric acid (concentration> 10%) los yog siab kub: Monel K500 tsis tuaj yeem tiv thaiv corrosion hauv ib puag ncig no. Thaum qhov kub siab tshaj 60 degree, txawm tias dilute hydrochloric acid yuav ua rau hnyav hnyav hnyav los yog pitting corrosion ntawm cov hlau, nrog rau hydrogen evolution. Nyob rau hauv cov concentrated hydrochloric acid, tus nqi corrosion tuaj yeem tshaj 1 hli / xyoo, ua rau cov khoom tawg sai sai lossis tsis ua haujlwm.
Muaj kev txwv kev thov: Monel K500 tsis pom zoo rau cov khoom siv hauv kev sib cuag ncaj qha nrog cov concentrated hydrochloric acid lossis kub dilute hydrochloric acid. Nws tsuas yog siv tau rau hauv cov xwm txheej tshwj xeeb ntawmkaw, deaerated dilute hydrochloric acid systems ntawm chav tsev kub.
2. Corrosion Resistance rau sulfuric acid
Dilute sulfuric acid (concentration Tsawg dua lossis sib npaug li 10%) ntawm chav tsev kub: Zoo ib yam li dilute hydrochloric acid, Monel K500 muaj corrosion kuj zoo nyob rau hauv deaerated dilute sulfuric acid, nrog ib tug corrosion ntawm tsawg tshaj li 0.05 hli / xyoo. Cov ntsiab lus npib tsib xee thiab tooj liab hauv cov hlau sib xyaw ua ke tsim cov yeeb yaj kiab tiv thaiv sulfate, uas cais cov matrix ntawm qhov nruab nrab corrosive.
Nruab nrab -concentration sulfuric acid (10% < concentration < 70%): Lub corrosivity ntawm sulfuric acid nce sharply nyob rau hauv no ntau yam. Nyob rau hauv chav tsev kub, tus nqi corrosion ntawm Monel K500 tuaj yeem ncav cuag 0.5-2 hli / xyoo; Thaum qhov kub nce mus txog 50℃lossis siab dua, pitting corrosion thiab intergranular corrosion yog qhov tshwm sim, uas tsis haum rau kev pabcuam ntev -.
Concentrated sulfuric acid (concentration Ntau dua los yog sib npaug rau 90%) ntawm chav tsev kub: Concentrated sulfuric acid has strong oxidizing properties, which can make the surface of Monel K500 form a dense passivation film composed of nickel sulfate and copper sulfate, thus showing excellent corrosion resistance (corrosion rate<=0.02 mm/year). Qhov no yog vim qhov muaj zog oxidizing ib puag ncig stabilizes zaj duab xis passivation thiab tiv thaiv nws los ntawm kev yaj los ntawm cov kua qaub. Txawm li cas los xij, thaum qhov kub siab tshaj 80 degree, cov zaj duab xis passivation yuav poob nws cov nyhuv tiv thaiv, thiab cov hlau yuav raug kev txom nyem loj heev.
Cov lus qhia txog kev siv tshuab: Monel K500 tuaj yeem siv rau cov khoom hauvchav -kub concentrated sulfuric acid systems(piv txwv li, cia tank hauv ob sab phlu, pipeline li qub), tab sis nws yuav tsum tau zam kom tiv tauj nruab nrab -concentration sulfuric acid los yog kub concentrated sulfuric acid.
3. Cov ntsiab lus tseem ceeb cuam tshuam rau kev tiv thaiv corrosion
Aeration mob: Cov pa oxygen hauv cov kua qaub yog qhov tseem ceeb ntawm kev ua kom muaj zog corrosion. Deaeration tuaj yeem txhim kho corrosion kuj ntawm Monel K500 hauv dilute acids; ntawm qhov tsis sib xws, aeration yuav ua rau thaj tsam corrosion.
Kub: Kub nce yuav exponentially nce tus nqi corrosion. Rau feem ntau cov kua qaub tawm, tus nqi corrosion ntawm Monel K500 doubles rau txhua txhua 20℃qhov kub thiab txias.
Cov impurity ions: Lub xub ntiag ntawm Cl⁻, Br⁻, Fe³⁺ thiab lwm yam ions yuav rhuav tshem cov zaj duab xis passivation ntawm lub alloy nto, inducing pitting corrosion thiab kev nyuaj siab corrosion cracking.
