Kev txheeb xyuas thiab kawm txog qhov teeb meem ntawm qhov kub tsis tshua muaj kev cuam tshuam kev ua haujlwm tsis ua haujlwm ntawm SA516Gr70 steel phaj nrog cov tuab tuab ntawm 34-58 hli tsis ntev los no, txhawm rau txiav txim siab qhov tseem ceeb ntawm qhov tsis zoo ntawm cov hlau phaj, thiab txhim kho qhov kub tsis tshua muaj kev cuam tshuam. kev ua tau zoo tus nqi ntawm cov hlau phaj los ntawm cov txheej txheem optimizations. Nyob rau tib lub sijhawm, muab cov ntaub ntawv txhawb nqa thiab kev taw qhia theoretical rau kev tsim khoom ntawm lwm cov qib steel zoo sib xws.
Kev siv ib puag ncig thiab mechanical zog ntawm steel phaj
Cov khoom tawg tawg, xws li hlau rau PTA (purified terephthalic acid) tej yaam num, yuav siv nyob rau hauv corrosive ib puag ncig. Hauv kev tsim cov vaj huam sib luag sib xyaw, SA516Gr70 steel daim hlau yog siv los ua cov substrates thiab hlau T composites, uas tuaj yeem siv tag nrho cov khoom tiv thaiv corrosion ntawm T daim hlau thiab tseem muab kev txhawb nqa rau SA516Gr70 steel daim hlau.
Vim qhov chaw ntawm qhov project yog nyob rau hauv ib cheeb tsam txias, nws yuav tsum tau hais tias cov hlau phaj tseem muaj kev cuam tshuam zoo toughness nyob rau hauv ib tug tsawg kub ib puag ncig ntawm -35 degree , thiab qhov cuam tshuam lub zog tom qab simulated mus ntev tom qab vuam kub. kev kho mob ntawm (565+10) degree x17 h tseem tuaj yeem ncav cuag tus nqi yam tsawg kawg nkaus ntawm 60J, txhawm rau ua kom tau raws li qhov yuav tsum tau muaj qhov nruab nrab qhov cuam tshuam lub zog ntawm cov phaj sib xyaw tawg tom qab kev ntxhov siab yuav tsum ntau dua 41J.
C yog lub ntsiab tseem ceeb thib ob rau Fe, uas tuaj yeem cuam tshuam ncaj qha rau lub zog, plasticity, toughness, thiab vuam kev ua tau zoo ntawm cov hlau. Xav txog qhov cuam tshuam ntawm C lub hauv paus ntawm kev ua kom muaj zog ntawm cov hlau thiab cov nag lossis daus ntawm cov carbides tsim nrog cov kab lus Nb, V, thiab lwm yam, cov ntsiab lus ntawm C yog tswj nyob rau hauv thaj tsam ntawm {{0}}}. 16% mus rau 0.18%. Nb thiab V cov ntsiab lus ua lub luag haujlwm hauv kev kho cov nplej loj thiab nag lossis daus ntxiv rau hauv kev tswj dov. Txhawm rau kom siv tag nrho lub luag haujlwm ntawm Nb alloy, cov khoom siv tshuaj Nb precipitates thiab aggregates ntawm cov kab dislocation thaum kub kub dov. Raws li nws cov concentration nce thiab nws cov txiaj ntsig pinning yog exerted, nws exerts muaj zog rub ntawm dislocation nce, ua rau nws nyuaj rau tsim cov ntsiab lus nucleation rau recrystallization. Yog li ntawd, ntxiv Nb tuaj yeem ua tiav qhov kub kub dov hauv thaj chaw uas tsis yog recrystallization (dov kub<950 ℃). The rolling process can form a large number of distortion bands to provide more nucleation points for ferrite phase transformation, promote ferrite phase transformation to form more refined grains, and improve the impact toughness of ferrite matrix. V elements mainly participate in the y → α transformation. During the process, the precipitation between phases and within the ferrite is strengthened, resulting in a higher volume fraction and density of the precipitated phase
Saib xyuas thiab txheeb xyuas cov qauv metallographic ntawm cov tsis tsim nyog batch ntawm steel daim hlau, raws li qhia nyob rau hauv daim duab 1. Los ntawm daim duab 1, nws yuav pom tau hais tias muaj ib lub zos non-uniformity nyob rau hauv lub metallographic qauv, nrog ib tug me me ntawm cov khoom sib xyaw crystals tshwm. Mixed crystals muaj qhov cuam tshuam loj tshaj plaws ntawm cov khoom siv hluav taws xob ntawm cov hlau phaj, tshwj xeeb tshaj yog qhov cuam tshuam rau qhov kub thiab txias. Nyob rau tib lub sijhawm, cov qauv sawb ntawm cov khoom tsis tsim nyog ntawm cov hlau phaj yog qhov pom tseeb dua, nrog rau cov nplej loj ntawm 8-9 qib.
