Hlau thiab nickel thiab nickel alloy vuam, FAQ

Kev Taw Qhia

Thaum tsim cov khoom siv tshuaj lom neeg thiab roj av, txhawm rau txuag cov nickel kim, cov hlau feem ntau yog welded rau nickel thiab alloys.

Cov teeb meem tseem ceeb ntawm kev vuam

Thaum vuam, cov khoom tseem ceeb hauv qhov vuam yog hlau thiab nickel, uas muaj peev xwm ua kom tsis muaj qhov tsis sib xws thiab tsis tsim cov khoom sib xyaw ua ke. Feem ntau, cov ntsiab lus nickel hauv qhov vuam yog qhov siab, yog li nyob rau hauv thaj chaw sib xyaw ntawm qhov sib koom ua ke, tsis muaj txheej diffusion tsim. Qhov teeb meem tseem ceeb nrog kev vuam yog qhov nyiam ua rau muaj porosity thiab kub tawg hauv qhov vuam.

1. Qhov porosity

Thaum vuam hlau thiab nickel thiab nws cov alloys, cov yam tseem ceeb uas cuam tshuam rau kev tsim cov porosity hauv qhov vuam yog oxygen, nickel thiab lwm yam khoom sib xyaw.

① Cov nyhuv ntawm oxygen. Vuam, cov hlau ua kua yuav yaj ntau cov pa oxygen, thiab cov pa oxygen ntawm qhov kub siab thiab nickel oxidation, tsim NiO, NiO tuaj yeem cuam tshuam nrog hydrogen thiab carbon hauv cov hlau ua kua los tsim cov dej ua pa thiab carbon monoxide hauv cov pas dej ua kom khov, xws li lig dhau los khiav tawm, seem hauv qhov vuam ntawm qhov tsim ntawm porosity. Hauv nickel ntshiab thiab Q235-A submerged arc vuam ntawm hlau thiab nickel weld, nyob rau hauv cov ntaub ntawv ntawm nitrogen thiab hydrogen cov ntsiab lus tsis hloov pauv ntau, qhov siab dua cov ntsiab lus oxygen hauv qhov vuam, qhov siab dua tus lej ntawm cov qhov hauv qhov vuam.

② Cov nyhuv ntawm nickel. Hauv kev vuam hlau-nickel, qhov solubility ntawm oxygen hauv hlau thiab nickel txawv, qhov solubility ntawm oxygen hauv kua nickel ntau dua li hauv cov hlau kua, thaum qhov solubility ntawm oxygen hauv nickel khov kho me dua li hauv cov hlau khov kho, yog li ntawd, qhov solubility ntawm oxygen hauv nickel crystallization ntawm qhov kev hloov pauv sai sai yog qhov pom tseeb dua li hauv cov hlau crystallization ntawm qhov kev hloov pauv sai sai. Yog li ntawd, qhov nyiam ntawm porosity hauv qhov vuam thaum Ni yog 15% ~ 30% yog me me, thiab thaum Ni cov ntsiab lus loj, qhov nyiam ntawm porosity yog nce ntxiv mus rau 60% ~ 90%, thiab tus nqi ntawm cov hlau yaj yuav txo qis, yog li ua rau qhov nyiam ntawm kev tsim porosity kom loj dua.

③ Kev cuam tshuam ntawm lwm cov khoom sib xyaw. Thaum cov hlau-nickel vuam muaj manganese, chromium, molybdenum, txhuas, titanium thiab lwm yam khoom sib xyaw lossis ua raws li cov alloying, tuaj yeem txhim kho qhov tiv thaiv porosity ntawm vuam, qhov no yog vim manganese, titanium thiab txhuas, thiab lwm yam muaj lub luag haujlwm ntawm deoxygenation, thaum chromium thiab molybdenum txhim kho qhov solubility ntawm vuam hauv cov hlau khov. Yog li nickel thiab 1Cr18Ni9Ti stainless hlau vuam tiv thaiv porosity dua li nickel thiab Q235-A hlau vuam. Aluminium thiab titanium kuj tuaj yeem kho nitrogen hauv cov tshuaj ruaj khov, uas kuj tuaj yeem txhim kho qhov tiv thaiv porosity ntawm vuam.

2. Kev tawg ntawm cua sov

Cov hlau thiab nickel thiab nws cov alloys hauv qhov vuam, qhov laj thawj tseem ceeb rau kev tawg thermal yog tias, vim muaj nickel siab weld nrog dendritic lub koom haum, nyob rau ntawm ntug ntawm cov nplej coarse, concentrated nyob rau hauv ntau qhov chaw melting qis co-crystals, yog li ua rau kev sib txuas ntawm cov nplej tsis muaj zog, txo qhov tsis kam ntawm cov hlau vuam. Tsis tas li ntawd, cov ntsiab lus nickel ntawm cov hlau vuam yog siab dhau rau cov hlau vuam los tsim thermal cracking muaj kev cuam tshuam loj heev rau hlau-nickel weld, oxygen, sulfur, phosphorus thiab lwm yam impurities ntawm qhov vuam thermal cracking kuj muaj kev cuam tshuam loj heev.

Thaum siv cov pa oxygen uas tsis muaj oxygen, vim tias qhov zoo ntawm cov pa oxygen, sulfur, phosphorus thiab lwm yam tsis zoo hauv qhov vuam yuav txo qis, tshwj xeeb tshaj yog cov pa oxygen tsawg zuj zus, ua rau qhov tawg ntawm cov hlau tawg tsawg heev. Vim tias cov pas dej ua kom cov pa oxygen thiab nickel tuaj yeem tsim Ni + NiO eutectic, eutectic kub ntawm 1438 ℃, thiab cov pa oxygen kuj tseem tuaj yeem ua rau cov teeb meem ntawm sulfur muaj zog. Yog li thaum cov pa oxygen hauv qhov vuam siab, qhov tshwm sim ntawm kev tawg ntawm thermal yuav loj dua.

Mn, Cr, Mo, Ti, Nb thiab lwm yam khoom sib xyaw ua ke, tuaj yeem txhim kho qhov tawg ntawm cov hlau vuam. Mn, Cr, Mo, Ti, Nb yog cov neeg sawv cev metamorphic, tuaj yeem txhim kho lub koom haum vuam, thiab tuaj yeem cuam tshuam kev coj ntawm nws cov crystallization. Al, Ti kuj yog tus neeg sawv cev deoxidizing muaj zog, tuaj yeem txo cov pa oxygen hauv qhov vuam. Mn tuaj yeem tsim cov tshuaj refractory nrog S, MnS, uas txo cov teebmeem tsis zoo ntawm sulfur.

Cov khoom siv kho tshuab ntawm cov pob qij txha welded

Cov khoom siv kho tshuab ntawm cov hlau-nickel vuam sib koom ua ke muaj feem cuam tshuam nrog cov khoom siv hlau thiab cov txheej txheem vuam. Thaum vuam nickel ntshiab thiab cov hlau carbon qis, thaum Ni sib npaug hauv qhov vuam tsawg dua 30%, nyob rau hauv qhov txias sai ntawm qhov vuam, cov qauv martensite yuav tshwm sim hauv qhov vuam, ua rau qhov plasticity thiab toughness ntawm qhov sib koom ua ke poob qis. Yog li ntawd, txhawm rau kom tau txais qhov plasticity thiab toughness zoo dua ntawm qhov sib koom ua ke, Ni sib npaug hauv qhov vuam hlau-nickel yuav tsum ntau dua 30%.