Welding Compatibility Assessment and Welding Consumable Selection Technology for Foreign Standard Rails
Dab tsi yog cov cim tseem ceeb rau kev ntsuas kev sib tw vuam ntawm cov txheej txheem thoob ntiaj teb, thiab lawv cuam tshuam li cas rau kev xaiv cov txheej txheem vuam?
Cov cim tseem ceeb rau kev ntsuas qhov vuam sib raug zoo ntawm cov txheej txheem thoob ntiaj teb yogcarbon sib npaug (Ceq)thiabcrack rhiab heev index (Pcm), uas ncaj qha cuam tshuam qhov vuam tawg nyiam ntawm txoj kev tsheb ciav hlau. Qhov siab dua qhov sib npaug ntawm cov pa roj carbon monoxide, qhov pom tseeb dua qhov kev sib tw ntawm txoj kev tsheb ciav hlau, qhov yooj yim dua rau cov kab nrib pleb thaum lub sij hawm vuam, thiab qhov phem dua qhov vuam sib xws; Thaum cov pa roj carbon sib npaug tsawg dua lossis sib npaug li 0.45%, qhov weldability yog qhov zoo, thiab cov txheej txheem flash vuam tuaj yeem siv tau. Qhov kev sib tw rhiab heev Performance index tsom rau kev ntsuas qhov cuam tshuam ntawm alloying ntsiab ntawm cov kab nrib pleb. Qhov loj dua tus nqi Pcm, qhov siab dua qhov kev pheej hmoo ntawm cov kab nrib pleb hauv qhov sib koom welded. Cov pa roj carbon sib npaug ntawm UIC60 rail yog kwv yees li 0.42%, uas muaj cov vuam zoo sib xws thiab tuaj yeem hloov kho rau cov txheej txheem flash welding hauv Suav teb; Cov pa roj carbon sib npaug ntawm ASTM136 Qib 4 rail yog 0.50%, uas muaj cov vuam tsis zoo thiab yuav tsum muaj txheej txheem vuam ua ntej. Yog li, kev ntsuam xyuas ob qhov ntsuas no yog lub hauv paus rau kev txiav txim siab qhov kub thiab txias, tuav lub sijhawm thiab tom qab- vuam txheej txheem kev kho cua sov.
Yuav ua li cas vuam kev sib koom ua ke tsis xws luag yuav tshwm sim los ntawm kev tsis sib haum xeeb ntawm cov txheej txheem thoob ntiaj teb thiab cov khoom siv vuam hauv teb chaws?
Qhov tsis sib haum xeeb ntawm cov txheej txheem thoob ntiaj teb thiab cov txheej txheem vuam cov ntaub ntawv hauv lub tebchaws yuav ua ntej ua rau lub zog tsis zoo ntawm cov welded sib koom ua ke. Yog hais tias lub zog ntawm cov khoom siv vuam yog qis dua li ntawm cov hlau rail hlau, qhov sib koom ua ke yog qhov ua rau cov yas deformation nyob rau hauv lub tsheb ciav hlau load, tsim ib qho kev sib koom ua ke tsis zoo; Yog hais tias lub zog ntawm cov khoom siv vuam yog siab dhau lawm, qhov sib koom ua ke toughness tsis txaus, thiab cov pob txha tawg tuaj yeem tshwm sim. Qhov thib ob, nws yuav ua rau vuam tawg. Qhov tsis sib haum xeeb ntawm cov hlau sib xyaw ntawm cov khoom siv vuam thiab cov tsheb ciav hlau yuav ua rau muaj qhov sib txawv loj hauv kev nthuav dav coefficient ntawm cov hlau vuam thiab cov hlau hauv paus, ua rau muaj kev ntxhov siab loj heev thaum lub sij hawm txias txias, thiab ua rau kub tawg lossis tawg tawg. Tsis tas li ntawd, nws yuav ua rau weld porosity thiab slag suav nrog. Lub peev xwm deoxidation ntawm cov khoom siv vuam tsis tuaj yeem phim cov khoom siv tsheb ciav hlau, thiab cov pa roj thiab impurities hauv lub pas dej molten tsis tuaj yeem raug tshem tawm zoo thaum lub sij hawm vuam, ua rau tsis zoo weld compactness. Cov teeb meem no yuav txo tau lub neej qaug zog ntawm kev sib koom ua ke welded thiab cuam tshuam rau kev nyab xeeb ntawm kev ua haujlwm ntawm kab.
Vim li cas cov khoom siv vuam tshwj xeeb nrog cov ntsiab lus siab manganese nyiam thaum vuam UIC rails?
UIC rails (xws li UIC900A/B) yog cov ntsiab lus siab manganese (1.0%-1.5%). Manganese tuaj yeem txhim kho lub zog thiab tawv ntawm txoj kev tsheb nqaj hlau thiab txhim kho weldability. Ua ntej xaiv cov khoom siv vuam tshwj xeeb nrog cov ntsiab lus ntawm cov manganese siab tuaj yeem ua kom cov alloy muaj pes tsawg leeg ntawm cov hlau vuam zoo ib yam li ntawm UIC rail base hlau, xyuas kom lub synchronization ntawm txhua yam khoom thiab expansion coefficients ntawm lub weld thiab lub hauv paus hlau, thiab txo vuam kev nyuaj siab. Manganese kuj muaj cov txiaj ntsig zoo deoxidation thiab desulfurization, uas tuaj yeem txo qhov tshwm sim ntawm weld porosity, slag suav nrog thiab kub tawg, thiab txhim kho weld compactness. Yog tias siv cov khoom siv qis-manganese zoo tib yam siv, cov ntsiab lus manganese ntawm cov hlau vuam tsis txaus, uas yuav ua rau lub zog vuam thiab lub zog qis dua li cov hlau hauv paus, thiab cov welded sib koom ua rau qaug zog puas tsuaj. Yog li ntawd, tshwj xeeb flash vuam cov ntaub ntawv nrog manganese cov ntsiab lus Ntau dua los yog sib npaug rau 1.2% yuav tsum tau xaiv rau UIC rail welding kom ua tau raws li kev sib koom ua ke.
Thaum vuam cov txheej txheem thoob ntiaj teb hauv zos, yuav ua li cas kho qhov ua ntej -weld preheating kub raws li cov khoom?
Lub pre-weld preheating kub rau hauv zos welding ntawm thoob ntiaj teb tus qauv rails yog tsuas yog raws li cov carbon sib npaug thiab alloy ntsiab ntsiab lus ntawm txoj kev tsheb nqaj hlau. Qhov siab dua cov pa roj carbon sib npaug, qhov siab dua qhov preheating kub yuav tsum tau. Rau JIS SKZ3 rails nrog cov pa roj carbon sib npaug Tsawg dua lossis sib npaug li 0.40%, qhov weldability yog qhov zoo, thiab tsis muaj preheating lossis tsuas yog qis -kub preheating (50-80 degree) yog yuav tsum tau kom tsis txhob muaj kab nrib pleb. Rau UIC900B rails nrog cov pa roj carbon sib npaug ntawm 0.40% -0.48%, qhov ntsuas kub ua ntej yuav tsum tau tswj ntawm 100-150℃kom txo qhov cua txias ntawm qhov chaw vuam thiab txo qhov tsim ntawm cov txheej txheem hardened. Rau ASTM136 Qib 4 rails nrog carbon sib npaug ＞ 0.48%, qhov kub ua ntej yuav tsum tau nce mus rau 180-220 degree. High-temperature preheating slows tus nqi txias, tso welding kev nyuaj siab, thiab tiv thaiv ncua kev tawg. Lub preheating kub yuav tsum uniformly npog lub 100mm ntau yam ntawm txoj kev tsheb ciav hlau vuam kawg kom tsis txhob muaj kev ntxhov siab tsis sib xws los ntawm lub zos preheating tsis txaus.
Cov teeb meem dab tsi yog qhov kev tshaj tawm -weld kev kho cua sov ntawm thoob ntiaj teb tus qauv rail welded pob qij txha feem ntau daws tau?
Lub hom phiaj tseem ceeb ntawm kev tshaj tawm -weld tshav kub kev kho mob ntawm cov txheej txheem thoob ntiaj teb rail welded pob qij txha yog txhawm rau tshem tawm cov welding residual kev ntxhov siab, kho cov qauv sib koom ua ke, thiab txhim kho kev sib koom ua ke, feem ntau daws peb qhov teeb meem tseem ceeb. Ua ntej, tshem tawm welding residual stress. Lub tensile stress generated thaum lub sij hawm welding tuaj yeem ua rau cov pob qij txha tawg yooj yim. Los ntawm siab -kub tempering ntawm 600-650 degree, qhov kev ntxhov siab seem tuaj yeem raug txo los ntawm 30%-50%. Thib ob, kho cov nplej. Cov nplej hauv qhov cua sov- thaj tsam cuam tshuam yuav coarsened vim qhov kub thiab txias, ua rau txo qhov tawv. Tom qab-weld kev kho cua sov tuaj yeem ua kom cov nplej ntxhib thiab rov ua kom tawv nqaij. Thib peb, tshem tawm cov txheej txheem hardened. Rau cov txheej txheem thoob ntiaj teb kev sib tw nrog cov ntsiab lus siab alloy, cov qauv nyuaj thiab nkig martensite tau yooj yim tsim nyob rau hauv qhov vuam kub- thaj tsam cuam tshuam. Tom qab vuam tempering tuaj yeem hloov lawv mus rau hauv tempered sorbite nrog zoo toughness. Tsis tas li ntawd, kev kho cua sov tom qab vuam tuaj yeem ua kom zoo sib xws ntawm kev sib koom ua ke, tswj qhov sib txawv ntawm qhov sib txawv ntawm qhov sib koom ua ke thiab lub hauv paus hlau hauv HB ± 20, thiab zam kev ntxhov siab los ntawm kev hloov pauv tam sim ntawd.