Kev tsim cov HIC Resistant Steels

Hydrogen induced cracking (HIC) sawv cev rau ib qho kev sib tw, tshwj xeeb tshaj yog nyob rau hauv cov roj av thiab refinery kev lag luam uas cov purity thiab tag nrho cov zoo ntawm cov hlau yog qhov tseem ceeb tshaj plaws.

Cov txheej txheem tsim khoom rau HIC resistant steels suav nrog cov txheej txheem tseem ceeb desulphurization nrog rau kev txhaj tshuaj magnesium thiab nplawm los ntawm hauv qab argon txhaj.

Kev tsim cov hlau huv yog ua raws li cov thev naus laus zis los tswj thiab / lossis tshem tawm cov kev suav nrog hauv cov hlau. Feem ntau, cov yam ntxwv thiab cov yam ntxwv ntawm cov hlau tsis muaj hlau sib xyaw ua ke muaj kev cuam tshuam tseem ceeb ntawm cov khoom siv hluav taws xob ntawm cov hlau thiab tseem txiav txim siab qhov huv ntawm cov hlau. Kev tsom xam meej ntawm cov yam ntxwv no yog li xav tau los txhim kho cov txheej txheem steelmaking los tsim cov hlau zoo.

Hydrogen induced cracking (HIC) thiab sulphide stress cracking (SSC) sawv cev rau ob hom hydrogen provoked kev puas tsuaj uas nquag ntsib hauv kev lag luam roj av thiab refinery. Hauv thawj rooj plaub (HIC), nws feem ntau lees paub tias qhov kev tiv thaiv ntawm cov hlau yog nyob ntawm lawv cov microstructural nta - cov khoom tsis yog xim hlau thiab kev sib cais.

Elongated manganese sulphides raug suav hais tias yog qhov chaw pib txaus ntshai tshaj plaws. Nyob rau hauv rooj plaub thib ob (SSC), nws ntseeg tau tias qhov kev tiv thaiv ntawm cov hlau tuaj yeem muaj feem cuam tshuam nrog lawv cov qib zog thaum cov yam ntxwv ntawm microstructure tsis tseem ceeb. Cov ntawv nthuav tawm no tau mob siab rau txoj kev tshawb fawb ntawm HIC thiab SSC hauv carbon-manganese steels, uas txawv ntawm lawv cov kev kho cua sov (microstructure, qib ntawm cov khoom siv kho tshuab) thiab lawv cov kev huv.

MnS suav nrog yog qhov tsim kev puas tsuaj loj tshaj plaws rau HIC, yog li, raws li kev ntsuas yooj yim, cov ntsiab lus ntawm cov sulfur yuav tsum raug txo rau cov hlau siv hauv cov kua qaub. Vim tias kev nce qib hauv cov txheej txheem steel, cov ntsiab lus ntawm cov sulfur tuaj yeem txo qis mus rau qib qis; nyob rau hauv 0.0008 wt. % (8 ppm).

Kev kho Ca feem ntau yog siv los tiv thaiv kev tsim ntawm elongated MnS thiab tswj cov sulfide suav nrog rau hauv cov duab kheej kheej, thiab yog tias muaj cov ntsiab lus Ca tsim nyog rau cov cuab yeej tawg. Yog tias cov ntsiab lus Ca tseem siab piv nrog S cov ntsiab lus, ntau tshaj Ca tuaj yeem tsim cov oxides uas tuaj yeem ua tus pib ntawm HIC. Ob peb qhov tsis zoo uas sawv cev rau cov ntsiab lus Ca muaj txiaj ntsig tau qhia, thiab cov ntsiab lus Ca yuav tsum tau ua tib zoo tswj hauv qhov nqaim; Piv txwv li, 3

Table 1: Tshuaj muaj pes tsawg leeg yuav tsum tau rau high-strength yeeb nkab steel, [ppm]

Daim duab 1 qhia txoj hauv kev rau HIC resistant steel ntau lawm. Ua ntej BOF txheej txheem, cov hlau kub yog desulphurized ntawm qhov chaw kub kub hlau desulphurization los ntawm kev txhaj tshuaj magnesium thiab CaO. Ntawm BOF, tsuas yog seem uas muaj cov ntsiab lus sulfur tsawg yuav tsum raug them. Cov txhuas rau deoxidation thiab cov slag forming agents ntxiv thaum tapping. Lub ntsiab alloying tseem ua tiav thaum lub sijhawm ntawd.

Lub ladle yog ces thauj mus rau qhov chaw nres tsheb bubbling qhov twg argon yog tshuab los ntawm ib sab saum toj lance thiaj li sib tov hlau thiab slag rau lub hom phiaj ntawm desulphurization. Tom qab ntawd, lub ladle yog pauv mus rau kev kho lub tshuab nqus tsev. Cov hlau yog nplawm los ntawm hauv qab argon txhaj tshuaj kom paub tseeb tias tob desulphurization thiab degassing.