Kev kho dehydrogenation, tseem hu ua dehydrogenation tshav kub kev kho mob, los yog kev kho cua sov tom qab vuam.
Lub hom phiaj ntawm kev kho cua sov tom qab vuam ntawm thaj chaw weld tam sim ntawd tom qab vuam yog txhawm rau txo qhov hardness ntawm thaj chaw weld, los yog tshem tawm cov teeb meem xws li hydrogen hauv thaj tsam weld. Hauv qhov no, kev kho tom qab cua sov thiab kev kho cua sov tom qab vuam muaj cov nyhuv tib yam.
Tom qab welding, lub tshav kub txo qhov txias ntawm lub vuam seam thiab welded sib koom ua ke los txhawb txoj kev khiav tawm ntawm hydrogen thiab tsis txhob nce hardness.
(1) Tom qab cua sov rau lub hom phiaj ntawm kev txhim kho kev ua tau zoo ntawm cov welded sib koom thiab txo nws cov hardness tsuas yog siv tau thaum lub vuam cheeb tsam tseem nyob rau hauv ib tug kuj kub kub tom qab vuam.
(2) Tom qab cua sov kom tsis txhob muaj qhov kub thiab txias yog qhov tseem ceeb los txhawb kev tshem tawm cov hluav taws xob txaus hauv qhov chaw vuam.
Kev tshem tawm ntawm hydrogen nyob ntawm qhov ntsuas kub thiab tuav lub sijhawm tom qab cua sov. Qhov ntsuas kub rau lub hom phiaj tseem ceeb ntawm kev tshem tawm hydrogen feem ntau yog 200-300 degrees, thiab lub sijhawm tom qab cua sov yog 0.5-1 teev.
Rau welds nyob rau hauv cov xwm txheej hauv qab no, kev kho mob tom qab cua sov tshem tawm hydrogen yuav tsum tau ua tam sim tom qab vuam (4 ntsiab lus):
(1) Thickness ntau dua 32mm, thiab cov khoom txheem tensile zog σb> 540MPa;
(2) Cov khoom siv hlau tsis tshua muaj hlau nrog lub thickness ntau dua 38mm;
(3) Lub pob tw weld nruab nrab ntawm lub embedded nozzle thiab lub nkoj siab;
(4) Kev ntsuas txheej txheem vuam txiav txim siab tias yuav tsum tau kho hydrogen tshem tawm.
Tus nqi ntawm qhov ntsuas kub tom qab cua sov feem ntau qhia los ntawm cov qauv hauv qab no:
Tp＝455.5[Ceq]p－111.4
Hauv cov mis, Tp —— tom qab cua sov kub ℃;
[Ceq]p — Carbon sib npaug mis.
[Ceq]p=C+0.2033Mn+0.0473Cr+0.1228Mo+0.0292Ni+0.0359Cu+0.0792Si－1.595P+1.692S+0.844V
Txhawm rau txo cov ntsiab lus hydrogen hauv thaj tsam weld yog ib qho tseem ceeb ntawm kev kho cua sov tom qab. Raws li cov lus ceeb toom, ntawm 298K, cov txheej txheem ntawm hydrogen diffusion los ntawm qis carbon steel welds yog 1.5 mus rau 2 lub hlis.
Thaum qhov kub thiab txias nce mus txog 320K, cov txheej txheem no tuaj yeem ua kom luv rau 2 mus rau 3 hnub thiab hmo ntuj, thiab tom qab cua sov rau 470K, nws yuav siv sij hawm 10 mus rau 15 teev.
Lub luag haujlwm tseem ceeb ntawm kev kho tom qab cua sov thiab dehydrogenation yog los tiv thaiv kev tsim cov kab mob khaub thuas hauv cov hlau los yog hauv thaj chaw uas muaj cua sov.
Thaum lub preheating ntawm weldment ua ntej vuam tsis txaus los tiv thaiv qhov tsim ntawm cov kab nrib pleb, xws li nyob rau hauv lub vuam ntawm high-constraint pob qij txha thiab nyuaj-rau-weld steels, cov txheej txheem tom qab cua sov yuav tsum tau siv los tiv thaiv kev tsim. ntawm cov kab nrib pleb txias.
Post lub sij hawm: Mar-29-2023
