Hlau weldability: kev faib tawm. Weldability pawg ntawm steels

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2024-01-02 13:55

Hlau yog cov khoom siv tseem ceeb. Nws yog hlau-carbon alloy uas muaj ntau yam impurities. Tag nrho cov khoom muaj nyob rau hauv nws muaj pes tsawg leeg cuam tshuam cov khoom ntawm lub ingot. Ib qho ntawm cov yam ntxwv thev naus laus zis ntawm cov hlau yog lub peev xwm los tsim cov pob qij txha zoo.

Yam uas txiav txim siab qhov kev sib tw ntawm cov hlau

Kev ntsuas ntawm qhov weldability ntawm cov hlau yog tsim los ntawm tus nqi ntawm qhov taw qhia tseem ceeb - cov pa roj carbon sib npaug ntawm С _{equiv. Qhov no yog ib qho kev coefficient uas coj mus rau hauv tus account qhov degree ntawm kev cuam tshuam ntawm cov ntsiab lus carbon thiab lub ntsiab alloying ntsiab ntawm cov yam ntxwv ntawm cov weld.}

Cov yam hauv qab no cuam tshuam rau kev sib txuas ntawm cov hlau:

1. Cov ntsiab lus carbon.
2. Kev muaj teeb meem impurities.
3. Degree ntawm doping.
4. Microstructure saib.
5. Environmental conditions.
6. Hlau thickness.

Cov lus qhia tshaj plaws yog cov tshuaj muaj pes tsawg leeg.

Kev faib cov hlau los ntawm pawg weldability

Tshuaj rauTag nrho cov xwm txheej no, qhov weldability ntawm steel muaj cov yam ntxwv sib txawv.

Kev faib cov hlau los ntawm kev sib txuas.

• Zoo (thaum С_{eq≧0, 25%): rau cov khoom siv carbon tsawg; tsis nyob ntawm qhov tuab ntawm cov khoom, huab cua puag, muaj kev npaj ua haujlwm.}
• Txaus siab (0.25% ≦С _{eq ≦0.35%): muaj kev txwv rau ib puag ncig thiab txoj kab uas hla ntawm cov qauv welded (cua kub txog -5, nyob twj ywm huab cua, thickness mus txog 20 mm).}
• Limited (0.35%≦C_{eq≦0.45%): Ua ntej cua sov yuav tsum tau ua kom zoo seam. Nws txhawb nqa kev hloov pauv "nruj" austenitic, tsim cov qauv ruaj khov (ferritic-pearlitic, bainitic).}
• Kev phem (С_{eq≧0, 45%): tsim kom muaj kev ruaj khov welded sib koom ua ke yog tsis yooj yim sua yam tsis muaj kev npaj kub dhau los ntawm cov npoo hlau, nrog rau kev kho cua sov tom qab ntawm welded qauv. Ntxiv cua sov thiab ua kom txias yog yuav tsum tau tsim cov microstructure xav tau.}

Steel weldability pawg ua kom yooj yim rau kev taw qhia cov yam ntxwv ntawm kev vuam tshwj xeeb ntawm cov hlau-carbon alloys.

kev kho cua sov

Nyob ntawm pab pawg ntawm weldability ntawm steels thiab cov khoom siv thev naus laus zis, cov yam ntxwv ntawm kev sib koom ua ke tuaj yeem hloov kho siv qhov kub thiab txias. Muaj 4 txoj hauv kev tseem ceeb ntawm kev kho cua sov: hardening, tempering,annealing thiab normalizing.

Feem ntau yog quenching thiab tempering rau hardness thiab ib txhij lub zog ntawm weld, kev nyuaj siab nyem, tiv thaiv tawg. Qhov degree ntawm tempering nyob ntawm cov khoom thiab cov khoom xav tau.

Kev kho cua sov ntawm cov qauv hlau thaum lub sijhawm npaj ua haujlwm yog ua tiav:

• annealing - txhawm rau txo kev ntxhov siab hauv cov hlau, ua kom nws softness thiab pliability;
• preheated kom txo qhov kub qhov sib txawv.

Kev tswj hwm qhov ntsuas kub muaj peev xwm tso cai:

• npaj ib feem rau kev ua haujlwm (txo tag nrho cov kev ntxhov siab sab hauv los ntawm kev sib tsoo nplej);
• txo qhov kub qhov sib txawv ntawm cov hlau txias;
• txhim kho qhov zoo ntawm cov khoom siv welded los ntawm thermally kho lub microstructure.

Kho cov khoom los ntawm qhov sib txawv ntawm qhov kub thiab txias tuaj yeem yog hauv zos lossis dav dav. Ntug cua sov yog ua los ntawm cov khoom siv roj lossis hluav taws xob arc. Cov qhov cub tshwj xeeb yog siv los ua kom sov tag nrho ib feem thiab ua kom nws txias.

Kev cuam tshuam ntawm microstructure ntawm cov khoom

Lub ntsiab lus ntawm cov txheej txheem kho cua sov yog ua raws li cov qauv kev hloov pauv hauv lub ingot thiab lawv cov txiaj ntsig ntawm cov hlau khov. Yog li, thaum rhuab mus rau qhov kub ntawm 727 ˚C, nws yog ib qho sib xyaw granular austenitic qauv. Txoj kev ua kom txias txiav txim siab txog kev hloov pauv:

1. Inside lub qhov cub (ceev 1˚C/min) - pearlite lug tsim nrog ib tug hardness ntawm txog 200 HB (Brinell hardness).
2. Nyobcua (10˚С/min) – sorbitol (ferrite-pearlite nplej), hardness 300 HB.
3. Oil (100˚C/min) – troostite (ferrite-cementite microstructure), 400 HB.
4. Dej (1000˚C / min) - martensite: nyuaj (600 HB) tab sis nkig acicular qauv.

Cov vuam sib txuas yuav tsum muaj qhov hardness txaus, lub zog, cov qauv zoo ntawm plasticity, yog li cov yam ntxwv martensitic ntawm seam tsis tau txais. Tsawg-carbon alloys muaj ferritic, ferrite-pearlitic, ferrite-austenitic qauv. Nruab nrab carbon thiab nruab nrab alloy steels - pearlitic. High-carbon thiab high-alloyed - martensitic los yog troostite, uas yog ib qho tseem ceeb rau coj mus rau ib tug ferritic-austenitic daim ntawv.

Mild steel vuam

Lub weldability ntawm carbon steels yog txiav txim los ntawm tus nqi ntawm cov pa roj carbon thiab impurities. Lawv muaj peev xwm hlawv tawm, tig mus rau hauv cov ntawv gaseous thiab muab cov seam porosity tsawg. Sulfur thiab phosphorus tuaj yeem ua kom muaj zog ntawm cov npoo ntawm cov nplej, ua rau cov khoom tawg yooj yim. Vuam yog qhov yooj yim tshaj plaws, txawm li cas los xij, xav tau ib tus neeg mus kom ze.

Cov pa roj carbon zoo zoo yog muab faib ua peb pawg: A, B thiab C. Vuam ua haujlwm nrog cov hlau ntawm pawg C.

Weldability ntawm steel qib VST1 - VST4, raws li GOST 380-94, yog tus cwj pwm los ntawm qhov tsis muaj kev txwv thiab kev xav tau ntxiv. Vuam ntawm qhov chaw nrog txoj kab uas hla mus txog 40 mm tshwm sim yam tsis muaj cua sov. Qhov ntsuas tau hauv qib: G - cov ntsiab lus siab ntawm manganese; kp, ps, cn - "boiling", "semi-calm", "kub"raws.

Cov pa roj carbon monoxide qis yog sawv cev los ntawm qib nrog rau kev tsim ntawm ntau pua ntawm cov pa roj carbon monoxide, qhia txog qib ntawm deoxidation thiab manganese cov ntsiab lus (GOST 1050-88): steel 10 (kuj 10kp, 10ps, 10G), 15 (kuj 15kp, 15ps, 15G), 20 (kuj 20kp, 20ps, 20G).

Txhawm rau kom muaj qhov vuam zoo, nws yog ib qho tsim nyog yuav tsum ua tiav cov txheej txheem ntawm cov pas dej saturation nrog carbon C thiab manganese Mn.

Vuam txoj kev:

1. Phau ntawv arc siv tshwj xeeb, pib calcined electrodes, nrog ib txoj kab uas hla ntawm 2 mus rau 5 hli. Hom: E38 (rau nruab nrab lub zog), E42, E46 (rau lub zog zoo txog li 420 MPa), E42A, E46A (rau lub zog siab ntawm cov txheej txheem nyuaj thiab lawv cov haujlwm hauv cov xwm txheej tshwj xeeb). Vuam nrog OMM-5 thiab UONI 13/45 rods yog ua nyob rau hauv qhov kev txiav txim ntawm ncaj qha tam sim no. Ua hauj lwm nrog electrodes TsM-7, OMA-2, SM-11 yog nqa tawm nrog ib tug tam sim no ntawm tej yam ntxwv.
2. Gas welding. Feem ntau tsis xav tau, tab sis ua tau. Nws yog nqa tawm siv cov xaim xaim Sv-08, Sv-08A, Sv-08GA, Sv-08GS. Nyias low-carbon hlau (d 8mm) yog welded nyob rau hauv txoj kev sab laug, tuab (d 8mm) - nyob rau hauv txoj cai. Qhov tsis zoo hauv cov khoom ntawm cov seam tuaj yeem raug tshem tawm los ntawm normalizing lossis annealing.

Vuam ntawm cov pa roj carbon tsawg yog ua yam tsis muaj cua sov ntxiv. Rau cov ntsiab lus ntawm daim ntawv yooj yim, tsis muaj kev txwv. Nws yog ib qho tseem ceeb los tiv thaiv cov qauv ntim thiab cov lattice los ntawm cua. Nws yog ntshaw kom weld complex khoom nyob rau hauv ib tug rhiav ntawm ib tug kub tsis qis tshaj 5˚С.

Yog li, rau qib VST1 - VST4, steel 10 - steel 20 - weldability yog zoo, xyaumyam tsis muaj kev txwv, yuav tsum muaj tus qauv xaiv ntawm cov txheej txheem vuam, hom electrode thiab cov yam ntxwv tam sim no.

Nruab nrab thiab siab carbon structural steels

Saturation ntawm alloy nrog carbon txo nws lub peev xwm los tsim cov tebchaw zoo. Nyob rau hauv tus txheej txheem ntawm thermal los ntawm ib tug arc los yog ib tug pa taws, sulfur accumulates raws cov npoo ntawm cov nplej, ua rau liab brittleness, phosphorus rau txias brittleness. Feem ntau, cov ntaub ntawv alloyed nrog manganese yog welded.

Qhov no suav nrog cov qauv hlau zoo tib yam VSt4, VSt5 (GOST 380-94), zoo 25, 25G, 30, 30G, 35, 35G, 40, 45G (GOST 1050-88) ntawm ntau yam metallurgical ntau lawm.

Lub ntsiab lus ntawm kev ua haujlwm yog txo qis cov pa roj carbon monoxide hauv lub pas dej ua ke, saturate cov hlau hauv nws nrog silicon thiab manganese, thiab ua kom pom kev siv tshuab. Nyob rau tib lub sijhawm, nws yog ib qho tseem ceeb los tiv thaiv cov pa roj carbon ntau dhau, uas tuaj yeem ua rau muaj kev puas tsuaj ntawm cov khoom siv kho tshuab.

Cov yam ntxwv ntawm vuam nrog nruab nrab thiab siab carbon steels:

1. pib ntug cua sov txog 100-200˚С kom dav txog 150 hli. Tsuas yog qib Vst4 thiab steel 25 yog welded yam tsis muaj cua sov ntxiv. Rau nruab nrab-carbon steels nrog zoo weldability, tag nrho normalization yog nqa tawm ua ntej pib ua hauj lwm. Pre-annealing yog yuav tsum tau rau high-carbon steels.
2. Arc vuam yog nqa tawm nrog coated calcined electrodes, xws li qhov loj ntawm 3 mus rau 6 hli (OZS-2, UONI-13/55, ANO-7), raws li tam sim no. tuaj yeem ua haujlwm hauvflux lossis shielding gases (CO_{2, argon).}
3. Gas welding yog nqa tawm nrog cov nplaim hluav taws xob, sab laug tes txoj kev, nrog preheating mus rau qhov kub ntawm 200˚C, nrog ib tug tsis tshua muaj zog mov ntawm acetylene.
4. Yuav tsum tau kho cua sov ntawm qhov chaw: hardening thiab tempering los yog cais tempering kom txo cov kev ntxhov siab nyob rau hauv, tiv thaiv cracking, soften hardened martensitic thiab troostite lug.
5. Kev sib cuag qhov chaw vuam yog ua yam tsis muaj kev txwv.

Yog li, nruab nrab- thiab siab-carbon cov qauv hlau yog welded xyaum tsis muaj kev txwv, ntawm qhov kub thiab txias ntawm qhov tsawg kawg 5˚С. Ntawm qhov kub thiab txias, thawj zaug preheating thiab kev kho cua sov zoo yog qhov yuav tsum tau ua.

vuam ntawm cov hlau tsis tshua muaj hlau

Alloy steels yog cov hlau uas muaj ntau yam hlau thaum lub sij hawm melting thiaj li tau txais cov khoom uas xav tau. Yuav luag tag nrho cov ntawm lawv muaj qhov zoo ntawm hardness thiab lub zog. Chrome thiab npib tsib xee yog ib feem ntawm tshav kub-resistant thiab stainless alloys. Vanadium thiab silicon muab elasticity, yog siv los ua cov khoom siv rau kev tsim cov springs thiab springs. Molybdenum, manganese, titanium nce hnav tsis kam, tungsten - liab hardness. Nyob rau tib lub sijhawm, zoo cuam tshuam rau cov khoom ntawm qhov chaw, lawv ua rau cov weldability ntawm hlau tsis zoo. Tsis tas li ntawd, qhov degree ntawm hardening thiab tsim cov qauv martensitic, kev ntxhov siab sab hauv thiab kev pheej hmoo ntawm kev tawg hauv seams nce.

Lub weldability ntawm alloy steels kuj txiav txim los ntawm lawvtshuaj muaj pes tsawg leeg.

Low-alloyed low-carbon steels 2GS, 14G2, 15G, 20G (GOST 4543-71), 15HSND, 16G2AF (GOST 19281-89) zoo welded. Raws li cov qauv txheej txheem, lawv tsis tas yuav muaj cua sov ntxiv thiab kev kho cua sov thaum kawg ntawm cov txheej txheem. Txawm li cas los xij, qee qhov kev txwv tseem muaj:

• Nov ntau yam ntawm kev tso cai thermal.
• Ua haujlwm yuav tsum tau ua ntawm qhov kub tsis qis dua -10˚С (nyob rau hauv cov xwm txheej ntawm qhov cua sov qis, tab sis tsis qis dua -25˚С, siv preheating txog 200˚С).

txoj kev muaj peev xwm:

• Hluav taws xob arc vuam nrog ncaj qha tam sim no 40 txog 50 A, electrodes E55, E50A, E44A.
• Tsis siv neeg submerged arc vuam siv cov xaim xaim Sv-08GA, Sv-10GA.

Lub weldability ntawm steel 09G2S, 10G2S1 kuj zoo, cov yuav tsum tau thiab ua tau txoj kev ntawm kev siv yog tib yam li alloys 12GS, 14G2, 15G, 20G, 15KhSND, 16G2AF. Cov yam ntxwv tseem ceeb ntawm cov alloys 09G2S, 10G2S1 yog qhov tsis muaj qhov xav tau los npaj cov npoo rau qhov chaw nrog txoj kab uas hla mus txog 4 cm.

Vuam ntawm nruab nrab alloy steels

Medium-alloyed steels 20KhGSA, 25KhGSA, 35KhGSA (GOST 4543-71) ua rau muaj kev tiv thaiv ntau dua rau kev tsim cov seams xoob. Lawv yog cov pab pawg neeg uas txaus siab weldability. Lawv yuav tsum tau preheating rau qhov kub ntawm 150-200˚С, multilayer welds, hardening thiab tempering thaum ua tiav ntawm vuam. Options:

• tam sim no thiab electrode txoj kab uas hla thaum vuam nrog hluav taws xob arcyog xaiv nruj me ntsis raws li cov thickness ntawm cov hlau, coj mus rau hauv tus account lub fact tias thinner npoo yog hardened ntau thaum ua hauj lwm. Yog li, nrog rau cov khoom lag luam txoj kab uas hla ntawm 2-3 hli, tus nqi tam sim no yuav tsum tsis pub dhau 50-90 A. Nrog rau ntug tuab ntawm 7-10 hli, qhov ncaj ncaj tam sim no ntawm qhov rov qab polarity nce mus rau 200 A siv electrodes 4-6 hli. Rods nrog cellulose los yog calcium fluoride tiv thaiv txheej (Sv-18KhGSA, Sv-18KhMA) yog siv.
• Thaum ua haujlwm hauv qhov chaw tiv thaiv roj CO_{2 nws yog qhov yuav tsum tau siv cov xaim Sv-08G2S, Sv-10G2, Sv-10GSMT, Sv-08Kh3G2SM nrog txoj kab uas hla. mus txog 2 mm.}

Txoj kev argon arc lossis submerged arc vuam feem ntau siv rau cov ntaub ntawv no.

Kub resistant thiab siab zog steels

Vuam nrog kub-resistant hlau-carbon alloys 12MX, 12X1M1F, 25X2M1F, 15X5VF yuav tsum tau nqa tawm nrog preheating rau kub ntawm 300-450˚С, nrog zaum kawg hardening thiab siab tempering.

• Electric arc vuam nyob rau hauv ib txoj kev cascade los tsim ib tug multilayer seam, siv calcined coated electrodes UONII 13 / 45MH, TML-3, TsL-30-63, TsL-39.
• Gas welding with acetylene supply 100 dm3/mm siv cov khoom muab tub lim Sv-08KhMFA, Sv-18KhMA. Cov yeeb nkab txuas yog ua nrog cov cua kub dhau los ntawm tag nrho cov sib koom ua ke.

Thaum welding nruab nrab-alloyed high-strength cov ntaub ntawv 14Kh2GM, 14Kh2GMRB, nws yog ib qho tseem ceeb kom ua raws li cov kev cai tib yam li rau tshav kub-resistant steels, coj mus rau hauv tus account ib co nuances:

• Kev tu kom huvntug thiab siv tacks.
• Kub-kub annealing ntawm electrode (txog 450˚C).
• Preheat mus txog 150˚C rau qhov ntau tshaj 2 cm tuab.
• Slow seam txias.

High alloy steels

Kev siv cov cuab yeej tshwj xeeb yog tsim nyog thaum vuam high-alloy steels. Cov no suav nrog ntau yam ntawm stainless, kub-resistant thiab kub-resistant alloys, ib co ntawm lawv: 09Kh16N4B, 15Kh12VNMF, 10Kh13SYu, 08Kh17N5MZ, 08Kh18G8N2T, 03Kh16N15MZB, 15Kh17. Weldability ntawm steels (GOST 5632-72) belongs rau pawg 4.

High carbon siab alloy steel weldability yam ntxwv:

1. Nws yog qhov tsim nyog los txo lub zog tam sim no los ntawm qhov nruab nrab ntawm 10-20% vim lawv cov thermal conductivity tsawg.
2. vuam yuav tsum tau nqa tawm nrog qhov sib txawv, electrodes txog li 2 hli loj.
3. Txo cov ntsiab lus ntawm phosphorus, lead, sulfur, antimony, ua kom cov nplua nuj ntawm molybdenum, vanadium, tungsten los ntawm kev siv cov pas nrig tshwj xeeb.
4. Qhov xav tau los tsim cov khoom sib xyaw weld microstructure (austenite + ferrite). Qhov no ua kom cov ductility ntawm cov hlau tso thiab txo qis ntawm kev ntxhov siab sab hauv.
5. Qhov yuav tsum tau ua kom sov ntawm qhov ua ntej ntawm vuam. Qhov ntsuas kub tau xaiv nyob rau hauv thaj tsam ntawm 100 txog 300˚С, nyob ntawm qhov microstructure ntawm cov qauv.
6. Kev xaiv ntawm coated electrodes hauv arc vuam yog txiav txim siab los ntawm hom nplej, khoom thiab kev ua haujlwm ntawm cov khoom: rau austenitic steel 12X18H9: UONII 13 / NZh, OZL-7, OZL-14 nrog Sv-06Kh19N9T txheej txheej,Sv-02X19H9; rau martensitic steel 20Kh17N2: UONII 10Kh17T, AN-V-10 coated nrog Sv-08Kh17T; rau austenitic-ferritic steel 12Kh21N5T: TsL-33 coated nrog Sv-08Kh11V2MF.
7. Thaum roj welding, cov khoom ntawm acetylene yuav tsum sib haum rau tus nqi ntawm 70-75 dm3 / hli, cov xaim xaim siv yog Sv-02Kh19N9T, Sv-08Kh19N10B.
8. Submerged arc ua haujlwm tau siv NZh-8.

Lub weldability ntawm steel yog ib tug txheeb ze parameter. Nws nyob ntawm cov tshuaj muaj pes tsawg leeg ntawm cov hlau, nws cov microstructure thiab lub cev muaj zog. Nyob rau tib lub sijhawm, lub peev xwm los tsim cov pob qij txha zoo tuaj yeem hloov kho nrog kev pab los ntawm kev xav txog kev siv tshuab zoo, cov cuab yeej tshwj xeeb thiab kev ua haujlwm.