Ntau yam kev sim cov txheej txheem (Brinell, Rockwell, Vickers) muaj cov txheej txheem tshwj xeeb rau qhov project hauv kev sim.The Rockwell T test yog tsim nyog rau kev tshuaj xyuas lub teeb phab ntsa raj los ntawm kev txiav lub raj ntev ntev thiab kuaj cov phab ntsa ntawm txoj kab uas hla sab hauv es tsis yog lub taub sab nraud.
Kev xaj ib lub raj yog me ntsis zoo li mus rau lub khw muag tsheb thiab xaj tsheb lossis tsheb thauj khoom.Hnub no, ntau txoj kev xaiv muaj tso cai rau cov neeg yuav khoom tuaj yeem kho lub tsheb hauv ntau txoj kev - xim sab hauv thiab sab nrauv, sab hauv cov pob zeb, cov kev xaiv sab nrauv, xaiv lub hwj chim, thiab lub suab kaw lus uas ze li kev sib tw hauv tsev kev lom zem.Tau tag nrho cov kev xaiv no, koj yuav tsis txaus siab.
Cov kav hlau hlau tsuas yog qhov ntawd.Nws muaj ntau txhiab txoj kev xaiv lossis cov kev qhia tshwj xeeb.Ntxiv rau qhov ntev, cov lus qhia tshwj xeeb sau cov tshuaj lom neeg thiab ntau yam khoom siv xws li qhov tsawg kawg nkaus yield zog (MYS), qhov kawg tensile zog (UTS), thiab yam tsawg kawg nkaus elongation ua ntej tsis ua hauj lwm.Txawm li cas los xij, ntau hauv kev lag luam-engineers, cov neeg ua haujlwm yuav khoom, thiab cov chaw tsim khoom-siv tau txais kev lag luam shorthands tsis muaj qhov xav tau tsuas yog siv cov yeeb nkab.
Sim xaj lub tsheb los ntawm ib tus yam ntxwv ("Kuv xav tau lub tsheb nrog kev sib kis tsis siv neeg") thiab koj yuav tsis mus deb dhau nrog tus neeg muag khoom.Nws yuav tsum tau ua daim ntawv xaj nrog ntau txoj kev xaiv.Cov yeeb nkab tsuas yog qhov ntawd - txhawm rau kom tau txais cov yeeb nkab zoo rau daim ntawv thov, cov yeeb nkab chaw tsim khoom xav tau cov ntaub ntawv ntau dua li qhov tawv tawv.
Yuav ua li cas hardness hloov mus rau lwm yam mechanical zog?Nws tej zaum yuav pib nrog ib tug yeeb nkab producer.Vim hais tias hardness testing yog ceev, yooj yim, thiab yuav tsum tau cov cuab yeej pheej yig, tube salespeople feem ntau siv hardness kuaj los piv ob lub raj.Yuav ua ib tug hardness xeem, txhua yam lawv xav tau yog ib tug du ntev ntawm cov yeeb nkab thiab ib tug xeem sawv ntsug.
Tube hardness correlates zoo nrog UTS, thiab raws li txoj cai ntawm tus ntiv tes xoo, feem pua ​​​​lossis feem pua ​​​​yog qhov muaj txiaj ntsig zoo hauv kev kwv yees MYS, yog li nws yooj yim los saib seb qhov kev ntsuas hardness yuav ua li cas thiaj tsim nyog rau lwm yam khoom.
Tsis tas li ntawd, lwm yam kev ntsuam xyuas yog qhov nyuaj.Thaum qhov kev sim hardness tsuas yog siv sijhawm ib feeb lossis yog li ntawm ib lub tshuab, MYS, UTS thiab elongation xeem yuav tsum tau ua qauv npaj thiab kev nqis peev tseem ceeb hauv cov khoom siv hauv chav kuaj loj.Raws li kev sib piv, nws yuav siv sij hawm vib nas this rau lub raj zeb tus neeg teb xov tooj los ua qhov kev sim hardness thiab cov sij hawm rau cov kws tshaj lij metallurgical technologies los ua ib qho nyuaj rau kev kuaj xyuas.
Qhov no tsis yog hais tias engineered yeeb nkab manufacturers tsis siv hardness test.Nws muaj kev ruaj ntseg hais tias feem ntau cov neeg ua, tab sis vim hais tias lawv ua gage repeatability thiab reproducibility ntsuam xyuas ntawm tag nrho lawv cov khoom xeem, lawv paub zoo txog cov kev txwv ntawm qhov kev xeem.Feem ntau siv kev ntsuam xyuas tube hardness raws li ib feem ntawm cov txheej txheem ntau lawm, tab sis lawv tsis siv nws los quantify raj / xeem dhau.
Vim li cas koj thiaj yuav tsum paub txog MYS, UTS thiab qhov tsawg kawg nkaus elongation?Lawv qhia tias lub raj yuav coj li cas hauv kev sib dhos.
MYS yog qhov tsawg kawg nkaus quab yuam uas ua rau cov khoom deformation mus tas li.Yog tias koj sim khoov ib txoj hlua ncaj (xws li lub tsho hanger) me ntsis thiab tso lub siab, ib qho ntawm ob yam yuav tshwm sim: nws yuav rov qab mus rau nws qhov qub qub (txoj kev ncaj) lossis nws yuav nyob twj ywm.Yog tias nws tseem ncaj, koj tsis tau txais yav dhau los MYS.Yog tias nws tseem khoov, koj twb.
Tam sim no, siv cov pliers los khi ob qhov kawg ntawm cov hlau.Yog tias koj tuaj yeem rhuav cov hlau rau hauv ob daim, koj dhau nws UTS.Koj muab ntau qhov nro rau nws thiab koj muaj ob lub xov hlau los qhia koj qhov kev siv zog superhuman.Yog tias qhov ntev ntawm cov xaim yog 5 ntiv tes, thiab ob qhov ntev tom qab tsis ua haujlwm ntxiv txog 6 ntiv tes, cov hlau yog ncab los ntawm 1%. - lub tswv yim rub hlau qhia txog UTS.
Cov qauv hlau photomicrograph yuav tsum tau txiav, polished, thiab etched siv cov kua qaub me me (feem ntau yog nitric acid thiab cawv (nitroethanol)) kom pom cov nplej.
Hardness yog ib qho kev sim ntawm seb cov khoom teb li cas rau qhov cuam tshuam.Xav txog qhov muab ib qho luv luv ntawm cov yeeb nkab rau hauv ib lub vise nrog serrated puab tsaig thiab tig lub vise kom kaw.Ntxiv rau flattening lub raj, lub puab tsaig ntawm lub vise kuj tawm indentations rau ntawm lub raj.
Qhov ntawd yog li cas qhov kev sim hardness ua haujlwm, tab sis nws tsis yog qhov ntxhib.Qhov kev sim no muaj kev tswj xyuas qhov loj me thiab tswj qhov siab.Cov quab yuam deform lub nto, tsim ib qho indentation los yog indentation.Qhov loj los yog qhov tob ntawm indentation txiav txim siab hardness ntawm cov hlau.
Rau kev ntsuam xyuas cov hlau, cov kev ntsuam xyuas nyuaj yog Brinell, Vickers, thiab Rockwell.Txhua qhov nws muaj nws tus kheej qhov ntsuas, thiab qee qhov muaj ntau txoj kev sim, xws li Rockwell A, B, thiab C.Rau cov kav hlau, ASTM Specification A513 hais txog Rockwell B test (abbreviated li HRB lossis RB).Rockwell B test ntsuas qhov sib txawv ntawm 1 lub taub me me ntawm cov hlau ua ntej. ntawm 100 kgf.A cov txiaj ntsig raug rau cov qauv me me yog HRB 60.
Cov ntaub ntawv kws tshawb fawb paub tias hardness yog linearly muaj feem xyuam rau UTS.Yog li ntawd, ib tug muab hardness yuav kwv yees UTS.Ib yam li ntawd, raj manufacturers paub hais tias MYS thiab UTS muaj feem xyuam.Rau welded yeeb nkab, MYS feem ntau yog 70% mus rau 85% ntawm UTS.Cov nqi pes tsawg yog nyob ntawm tus txheej txheem ntawm kev ua lub raj.The hardness ntawm HRB00 ib square meter ntawm UTS 60 pounds. SI) thiab MYS ntawm 80%, lossis 48,000 PSI.
Feem ntau cov yeeb nkab tshwj xeeb hauv kev tsim khoom yog qhov siab tshaj plaws hardness.Ntxiv rau qhov loj me, tus kws ua haujlwm tau txhawj xeeb nrog kev qhia txog lub welded hluav taws xob tsis kam welded (ERW) yeeb nkab nyob rau hauv ib qho kev ua haujlwm zoo, uas tuaj yeem ua rau qhov siab tshaj plaws hardness ntawm HRB 60 nrhiav nws txoj hauv kev ntawm cov khoom siv kos duab.
Ua ntej, lub hardness ntawm HRB 60 tsis qhia peb ntau.Qhov kev nyeem ntawv HRB 60 yog ib tug dimensionless naj npawb.Cov khoom soj ntsuam nrog HRB 59 yog softer dua cov khoom kuaj nrog HRB 60, thiab HRB 61 yog ib qho nyuaj tshaj li HRB 60, tab sis los ntawm ntau npaum li cas?Nws tsis tuaj yeem quantified zoo li lub ntim (measured) ( ntsuas nyob rau hauv qhov kev ncua deb txheeb ze rau lub sij hawm), los yog UTS ( ntsuas nyob rau hauv phaus ib square inch).Reading HRB 60 tsis qhia peb ib yam dab tsi tshwj xeeb.Qhov no yog ib yam khoom ntawm cov khoom, tab sis tsis yog lub cev khoom. Thib ob, hardness test tsis haum rau repeatability los yog reproducibility.Kev ntsuam xyuas ob qhov chaw ntawm ib qho kev xeem kuaj, txawm tias qhov kev ntsuam xyuas loj ntawm txhua qhov kev ntsuam xyuas no. yog qhov xwm txheej ntawm qhov kev sim.Tom qab ib txoj haujlwm tau ntsuas, nws tsis tuaj yeem ntsuas lub sijhawm thib ob los txheeb xyuas cov txiaj ntsig tau.Test repeatability tsis tau.
Qhov no tsis txhais hais tias kev sim hardness yog qhov tsis yooj yim.Qhov tseeb, nws muab cov lus qhia zoo rau cov khoom siv UTS, thiab nws yog qhov kev sim sai thiab yooj yim rau kev ua.Txawm li cas los xij, txhua tus neeg koom nrog kev qhia, kev yuav khoom thiab kev tsim cov raj yuav tsum paub txog nws cov kev txwv raws li qhov ntsuas ntsuas.
Vim hais tias "ib txwm" cov yeeb nkab tsis zoo, thaum xav tau, cov yeeb nkab manufacturers feem ntau nqaim nws mus rau ob feem ntau siv cov yeeb nkab steel thiab cov yeeb nkab hom tau teev tseg hauv ASTM A513: 1008 thiab 1010.Txawm tias tom qab tshem tawm tag nrho lwm hom raj, qhov ua tau zoo ntawm cov cuab yeej cuab tam ntawm ob hom raj hom no yog dav dav.
Piv txwv li, ib lub raj tau piav qhia tias yog mos yog MYS tsawg thiab elongation siab, uas txhais tau hais tias nws ua tau zoo dua nyob rau hauv tensile, deflection thiab teem dua ib lub raj piav raws li ib tug nyuaj, uas muaj ib tug kuj siab MYS thiab kuj tsis tshua muaj elongation.Qhov no zoo ib yam li qhov sib txawv ntawm cov mos thiab tawv hlau, xws li lub tsho tiv no hangers thiab drills.
Elongation nws tus kheej yog lwm yam uas muaj feem cuam tshuam rau kev siv yeeb nkab tseem ceeb.Tubes nrog elongation siab tuaj yeem tiv taus tensile rog;Cov ntaub ntawv uas tsis tshua muaj elongation yog nkig ntau dua thiab yog li ntawd ntau dua rau kev puas tsuaj rau kev qaug zog-hom tsis ua haujlwm.Txawm li cas los xij, elongation tsis ncaj qha rau UTS, uas yog tib yam khoom siv ncaj qha ntsig txog hardness.
Vim li cas cov khoom siv ntawm cov raj sib txawv heev? Ua ntej, cov tshuaj muaj pes tsawg leeg sib txawv.Steel yog cov khoom siv ntawm cov hlau thiab carbon thiab lwm yam tseem ceeb alloys.Rau qhov yooj yim, peb tsuas yog cuam tshuam nrog cov feem pua ​​​​ntawm no.Carbon atoms hloov qee cov hlau atoms, tsim cov qauv siv lead ua ntawm steel.ASTM 1008 yog ib qho tseem ceeb ntawm 0% cov ntsiab lus tshwj xeeb. uas tsim cov khoom tshwj xeeb thaum cov ntsiab lus carbon hauv cov hlau yog ultra-low.ASTM 1010 qhia cov ntsiab lus carbon ntawm 0.08% thiab 0.13%.
Thib ob, cov yeeb nkab steel tuaj yeem tsim los yog fabricated thiab tom qab ntawd ua tiav nyob rau hauv xya txoj kev tsim khoom sib txawv.ASTM A513 ntsig txog ERW yeeb nkab ntau lawm npe xya hom:
Yog hais tias cov tshuaj muaj pes tsawg leeg ntawm cov hlau thiab cov raj tsim cov kauj ruam tsis muaj kev cuam tshuam rau lub hardness ntawm cov hlau, yog dab tsi? Teb cov lus nug no txhais tau tias poring tshaj cov ntsiab lus.Qhov no begs ob nqe lus nug ntxiv: Dab tsi cov ntsiab lus, thiab nyob ze li cas?
Cov ntsiab lus hais txog cov nplej uas tsim cov hlau yog thawj cov lus teb.Thaum cov hlau yog tsim los ntawm lub hauv paus steel zeb, nws tsis txias rau hauv ib qho loj loj nrog ib qho tshwj xeeb.Raws li cov hlau txias, cov hlau cov molecules teeb tsa hauv cov qauv rov ua dua tshiab (crystals), zoo ib yam li snowflakes li cas.Tom qab cov pob zeb tau tsim, lawv sib sau ua ke rau hauv cov ntawv txias los yog cov ntawv loj hlob. Cov hlau molecules yog absorbed los ntawm cov nplej.Txhua qhov no tshwm sim ntawm qib microscopic vim tias qhov nruab nrab loj steel nplej yog li 64 µ lossis 0.0025 ntiv tes dav.While txhua cov nplej zoo ib yam li lwm yam, lawv tsis zoo ib yam.Lawv sib txawv me ntsis ntawm qhov loj me, kev taw qhia thiab cov ntsiab lus carbon.Qhov sib cuam tshuam ntawm cov nplej yog hu ua grain ciam teb.Thaum cov nplej tsis sib xws.
Koj yuav tsum saib deb npaum li cas kom pom cov nplej tsis pom kev? 100x magnification, lossis 100x tib neeg lub zeem muag, yog txaus.Txawm li cas los xij, tsuas yog saib cov hlau tsis kho ntawm 100 zaus lub zog tsis qhia ntau.Cov qauv yog npaj los ntawm polishing tus qauv thiab etching saum npoo nrog cov kua qaub (feem ntau nitric acid thiab cawv) hu ua nitroethanol etchant.
Nws yog cov nplej thiab lawv cov lattice sab hauv uas txiav txim siab qhov cuam tshuam lub zog, MYS, UTS thiab elongation steel tuaj yeem tiv taus ua ntej tsis ua haujlwm.
Steelmaking cov kauj ruam, xws li kub thiab txias dov ntawm sawb, siv kev ntxhov siab rau hauv cov qauv nplej;Yog tias lawv hloov pauv mus tas li, qhov no txhais tau hais tias qhov kev ntxhov siab deforms lub grain.Lwm cov txheej txheem ua, xws li coiling cov hlau rau hauv coils, uncoiling nws, thiab deforming steel nplej los ntawm ib lub raj zeb zeb (kom tsim thiab loj lub raj).Cold drawing lub raj ntawm lub mandrel kuj tso siab rau cov khoom, raws li kev tsim cov kauj ruam xws li kawg forming thiab bending cov qauv.
Cov kauj ruam saum toj no deplete lub ductility ntawm cov hlau, uas yog nws lub peev xwm los tiv thaiv tensile (rub-qhib) kev ntxhov siab.Steel ua nkig, uas txhais tau hais tias nws muaj feem ntau yuav tawg yog tias koj ua hauj lwm rau nws. Elongation yog ib feem ntawm ductility (compressibility yog lwm yam). Nws yog ib qho tseem ceeb kom to taub tias feem ntau tsis ua hauj lwm thaum lub sij hawm tensile kev nyuaj siab, tsis heev compression ntawm tensile zog. , steel deforms yooj yim nyob rau hauv compressive kev nyuaj siab - nws yog ductile - uas yog ib qho zoo dua.
Pob zeb muaj zog compressive siab tab sis tsis tshua muaj ductility piv rau cov pob zeb.Cov khoom no yog qhov txawv ntawm cov hlau.Yog li ntawd cov pob zeb siv rau txoj kev, cov tsev thiab cov kev taug kev yog feem ntau haum nrog rebar.Qhov tshwm sim yog cov khoom uas muaj zog ntawm ob cov ntaub ntawv: nyob rau hauv nro, steel muaj zog, thiab nyob rau hauv siab, pob zeb.
Thaum lub sij hawm ua hauj lwm txias, raws li cov ductility ntawm cov hlau txo, nws hardness nce.Ib lo lus, nws yuav harden.Raws li qhov teeb meem no, tej zaum yuav muaj txiaj ntsig;Txawm li cas los xij, nws yuav yog qhov tsis zoo vim tias qhov nyuaj yog sib npaug nrog brittleness.Qhov ntawd yog, raws li cov hlau ua nyuaj, nws ua tsis tshua muaj elastic;yog li ntawd, nws yuav ua tsis tiav.
Nyob rau hauv lwm yam lus, txhua kauj ruam txheej txheem siv ib co ntawm cov yeeb nkab ductility.Nws tau nyuaj raws li ib feem ua hauj lwm, thiab yog hais tias nws yog heev nyuaj nws yog ib qho yooj yim useless.Hardness yog brittleness, thiab ib tug brittle tube yuav ua tsis tau tejyam thaum siv.
Puas yog cov chaw tsim khoom puas muaj kev xaiv nyob rau hauv rooj plaub no?Nyob rau hauv luv luv, yog.Qhov kev xaiv yog annealing, thiab thaum nws tsis heev tej yam yees siv, nws yog ze rau khawv koob li koj tau.
Nyob rau hauv layman cov ntsiab lus, annealing tshem tawm tag nrho cov teebmeem ntawm lub cev kev nyuaj siab ntawm cov hlau.Qhov txheej txheem no heats cov hlau mus rau ib tug stress-relief los yog recrystallization kub, yog li tshem tawm dislocations.Vim qhov tshwj xeeb kub thiab lub sij hawm siv nyob rau hauv cov txheej txheem annealing, cov txheej txheem yog li restores ib co los yog tag nrho nws cov ductility.
Annealing thiab tswj cua txias txhawb cov qoob loo loj hlob.Qhov no tau txais txiaj ntsig yog tias lub hom phiaj yog txo cov brittleness ntawm cov khoom, tab sis kev tswj tsis tau cov qoob loo tuaj yeem soften cov hlau ntau dhau, ua rau nws siv tsis tau rau nws qhov kev npaj siv.Stopping tus txheej txheem annealing yog lwm yam nyob ze-magical tshaj plaws.Quenching ntawm qhov kub thiab txias nrog rau txoj cai quenching tus neeg sawv cev rau lub sij hawm sai.
Peb puas yuav tsum tso tseg qhov hardness specification? no.Hardness yam ntxwv muaj nuj nqis feem ntau raws li cov ntsiab lus siv thaum qhia cov kav dej steel.Ib qho kev ntsuas muaj txiaj ntsig, hardness yog ib qho ntawm ntau tus yam ntxwv uas yuav tsum tau teev tseg thaum xaj cov khoom siv tubular thiab kuaj xyuas thaum tau txais (thiab yuav tsum tau sau nrog txhua qhov khoom xa tuaj).
Txawm li cas los xij, nws tsis yog qhov tseeb rau kev tsim nyog (kev lees txais lossis tsis lees paub) cov khoom siv.Ntxiv rau hardness, cov tuam txhab tsim khoom yuav tsum sim qee zaus cov khoom xa tuaj los txiav txim siab lwm yam khoom muaj feem xyuam, xws li MYS, UTS, lossis tsawg kawg elongation, nyob ntawm daim ntawv thov ntawm lub raj.
Wynn H. Kearns is responsible for regional sales for Indiana Tube Corp., 2100 Lexington Road, Evansville, IN 47720, 812-424-9028, wkearns@indianatube.com, www.indianatube.com.
Tube & Pipe Journal tau dhau los ua thawj phau ntawv xov xwm mob siab rau ua haujlwm rau kev lag luam yeeb nkab hlau hauv xyoo 1990.Hnub no, nws tseem yog qhov kev tshaj tawm nkaus xwb hauv North America mob siab rau kev lag luam thiab tau dhau los ua cov ntaub ntawv ntseeg siab tshaj plaws rau cov kws tshaj lij yeeb nkab.
Tam sim no nrog kev nkag mus rau tag nrho cov ntawv digital ntawm FABRICATOR, yooj yim nkag mus rau cov khoom lag luam muaj txiaj ntsig.
Cov ntawv digital ntawm The Tube & Pipe Journal yog tam sim no nkag mus tau yooj yim, muab kev nkag tau yooj yim rau cov khoom lag luam muaj txiaj ntsig.
Txaus siab rau kev nkag mus rau tag nrho cov ntawv luam tawm digital ntawm STAMPING Journal, uas muab cov txheej txheem thev naus laus zis tshiab, kev coj ua zoo tshaj plaws thiab xov xwm kev lag luam rau kev lag luam hlau stamping.
Txaus siab rau kev nkag mus rau cov ntawv tshaj tawm digital ntawm Daim Ntawv Qhia Ntxiv kom kawm paub yuav ua li cas ntxiv kev tsim khoom tuaj yeem siv los txhim kho kev ua haujlwm zoo thiab nce cov txiaj ntsig.
Tam sim no nrog kev nkag mus rau tag nrho cov ntawv digital ntawm Tus Fabricator en Español, nkag tau yooj yim rau kev lag luam muaj txiaj ntsig.