Q345 yog ib hom hlau. Nws yog ib qho qis- alloy steel (C < 0.2%), dav siv hauv kev tsim kho, txuas hniav, tsheb, nkoj, nkoj siab, thiab lwm yam. "Q" sawv cev rau lub zog ntawm cov khoom siv no, thiab "345" qhia nws cov txiaj ntsig tawm los, uas yog kwv yees li 345 MPa. Tus nqi tawm los txo qis thaum lub thickness ntawm cov khoom nce.
Q345 muaj tag nrho cov khoom siv kho tshuab zoo, lees txais qis -kub kev ua haujlwm, thiab zoo plasticity thiab weldability. Nws yog siv rau nruab nrab thiab qis - cov hlab ntsha siab, cov roj tank, tsheb, cranes, mining machinery, fais fab nroj tsuag, txuas hniav, thiab lwm yam khoom raug rau dynamic loads, raws li zoo raws li cov neeg kho tshuab qhov chaw, lub tsev, thiab dav hlau structural Cheebtsam. Nws yog siv nyob rau hauv kub - dov los yog normalized tej yam kev mob thiab yuav siv tau nyob rau hauv ntau yam qauv nyob rau hauv txias cheeb tsam hauv qab no -40℃.
Duab Qib Classification
Q345 tau muab faib ua plaub qib: Q345A, Q345B, Q345C, Q345D, thiab Q345E. Qhov sib txawv tseem ceeb ntawm lawv yog lawv qhov kub thiab txias.
Q345A qib: Tsis muaj kev sim cuam tshuam;
Q345B qib: Kev ntsuas cuam tshuam ntawm 20℃(kub li qub);
Q345C qib: Kev ntsuas cuam tshuam ntawm 0 degree;
Q345D qib: Kev ntsuas cuam tshuam ntawm -20 degree;
Q345E qib: Kev ntsuas cuam tshuam ntawm -40 degree.
Qhov cuam tshuam qhov tseem ceeb sib txawv nyob ntawm qhov cuam tshuam qhov kub thiab txias.
Daim duab tshuaj muaj pes tsawg leeg
Q345A: C Tsawg dua lossis sib npaug 0.20, Mn Tsawg dua lossis sib npaug 1.7, Si Less dua lossis sib npaug 0.55, P Tsawg dua lossis sib npaug 0.045, S Tsawg dua lossis sib npaug 0.045, V 0.02 ~ 0.15;
Q345B: C Tsawg dua lossis sib npaug 0.20, Mn Tsawg dua lossis sib npaug 1.7, Si Less dua lossis sib npaug 0.55, P Tsawg dua lossis sib npaug 0.040, S Tsawg dua lossis sib npaug 0.040, V 0.02 ~ 0.15;
Q345C: C Tsawg dua lossis sib npaug 0.20, Mn Tsawg dua lossis sib npaug rau 1.7, Si Less dua lossis sib npaug rau 0.55, P Tsawg dua lossis sib npaug 0.035, S Tsawg dua lossis sib npaug 0.035, V 0.02 ~ 0.15, Al Ntau dua lossis sib npaug rau 0.015
Q345D: C Tsawg dua lossis sib npaug rau 0.20, Mn Tsawg dua lossis sib npaug rau 1.7, Si Less dua lossis sib npaug rau 0.55, P Tsawg dua lossis sib npaug 0.030, S Tsawg dua lossis sib npaug 0.030, V 0.02 ~ 0.15, Al Ntau dua lossis sib npaug rau 0.015
Q345E: C Tsawg dua lossis sib npaug 0.20, Mn Tsawg dua lossis sib npaug 1.7, Si Less dua lossis sib npaug rau 0.55, P Tsawg dua lossis sib npaug 0.025, S Tsawg dua lossis sib npaug 0.025, V 0.02 ~ 0.15, Al Ntau dua lossis sib npaug rau 0.015
Duab piv nrog 16Mn
Q345 steel yog hloov pauv rau ntau qib steel qub, suav nrog 12MnV, 14MnNb, 18Nb, 16MnRE, thiab 16Mn, tsis yog 16Mn steel xwb. Cov tshuaj muaj pes tsawg leeg ntawm 16Mn thiab Q345 kuj txawv.
Qhov tseem ceeb tshaj, cov thickness pab pawg qhov ntev ntawm ob lub steels raws li lawv lub zog tawm los sib txawv heev, uas yuav ua rau muaj kev hloov pauv hauv qhov kev cia siab ntawm cov ntaub ntawv ntawm qee cov thicknesses. Yog li ntawd, nws tsis tsim nyog tsuas yog siv qhov kev cia siab ntawm 16Mn steel rau Q345 steel; qhov kev ntxhov siab tso cai yuav tsum tau rov- txiav txim siab raws li qhov tshiab steel thickness pawg qhov ntev. Lub ntsiab tivthaiv ntawm Q345 steel yog qhov pib zoo ib yam li ntawm 16Mn steel, qhov sib txawv yog qhov sib ntxiv ntawm cov kab hlau rhuav tshem V, Ti, thiab Nb. Cov me me ntawm V, Ti, thiab Nb ua kom zoo dua cov qauv nplej, txhim kho cov hlau qhov tawv thiab tag nrho cov khoom siv kho tshuab.
Qhov no tseem tso cai rau kev tsim cov phaj tuab tuab. Yog li, tag nrho cov khoom siv kho tshuab ntawm Q345 steel yuav tsum zoo dua rau cov hlau 16Mn, tshwj xeeb tshaj yog nws qhov kev ua haujlwm kub qis, uas 16Mn steel tsis muaj. Qhov kev cia siab ntawm Q345 steel yog me ntsis siab dua li ntawm 16Mn steel.
Duab
Duab Kev sib piv
Q345D Seamless Steel Yeeb Nkab Mechanical Properties:
Tensile zog: 490-675 Nm; Yield Strength: Ntau dua lossis sib npaug rau 345 Nm; Elongation: Ntau dua lossis sib npaug li 22%
Q345B Seamless Steel Yeeb Nkab Mechanical Properties:
Tensile zog: 490-675 Nm; Yield Strength: Ntau dua lossis sib npaug rau 345 Nm; Elongation: Ntau dua lossis sib npaug li 21%
Q345A Seamless Steel Yeeb Nkab Mechanical Properties:
Tensile zog: 490-675 Nm; Yield Strength: Ntau dua lossis sib npaug rau 345 Nm; Elongation: Ntau dua lossis sib npaug li 21%
Q345C Seamless Steel Yeeb Nkab Mechanical Properties:
Tensile zog: 490-675 Nm; Yield Strength: Ntau dua lossis sib npaug rau 345 Nm; Elongation: Ntau dua lossis sib npaug li 22%
Q345E Seamless Steel Yeeb Nkab Mechanical Properties:
Tensile zog: 490-675 Nm; Yield Strength: Ntau dua lossis sib npaug rau 345 Nm; Elongation: Ntau dua lossis sib npaug li 22%
Duab Khoom Series
Kev sib piv ntawm Q345D steel nrog Q345A, B, thiab C steels. Qhov qis- qhov kub thiab txias cuam tshuam lub zog ntsuas kub yog qis. Nws muaj kev ua tau zoo. Cov ntsiab lus ntawm cov tshuaj phem P thiab S yog qis dua Q345A, B, thiab C.
Tus nqi lag luam yog siab dua Q345A, B, thiab C.
Q345d txhais: ① Nws muaj Q + tus lej + cim qib zoo + cov cim deoxidation. Nws qib steel yog prefixed nrog "Q," sawv cev rau lub ntsiab lus ntawm cov hlau. Cov lej hauv qab no qhia txog tus nqi taw tes tawm hauv MPa. Piv txwv li, Q235 sawv cev rau carbon structural steel nrog ib tug yield point (σs) ntawm 235 MPa.
② Yog tias tsim nyog, cov cim qhia txog qib zoo thiab cov txheej txheem deoxidation tuaj yeem muab ntxiv tom qab qib steel. Cov cim qib zoo yog A, B, C, thiab D.
Deoxidation txoj kev cim: F qhia rimmed steel; b qhia semi-tua steel; Z qhia tias tua hlau; TZ qhia tshwj xeeb tua hlau. Cov hlau tua yuav tsis muaj lub cim, piv txwv li, Z thiab TZ yuav raug tshem tawm. Piv txwv li, Q235-AF qhia qib A rimmed steel.
③ Carbon steel rau lub hom phiaj tshwj xeeb, xws li choj steel thiab marine steel, pib siv txoj kev xaiv rau carbon structural steel, tab sis nrog ib tsab ntawv ntxiv qhia txog daim ntawv thov ntxiv rau qhov kawg ntawm qib steel.
Q345 (Low Alloy High Strength Steel) - Cov ntaub ntawv tawm hauv online
Duab: Khoom Taw Qhia
1. Cov tshuaj muaj pes tsawg leeg ntawm Q345 muaj nyob rau hauv cov lus hauv qab no (%):
Element
C Tsawg dua los yog sib npaug
Mn
Si Less than los sib npaug
P Tsawg dua lossis sib npaug
S Tsawg dua los yog sib npaug
Al Greater dua los yog sib npaug
V
Nb
Ti
Cov ntsiab lus
0.2
1.0-1.6
0.55
0.035
0.035
0.015
0.02-0.15
0.015-0.06
0.02-0.2
2. Cov khoom siv kho tshuab ntawm Q345C tau qhia hauv cov lus hauv qab no (%):
Mechanical Properties Index
Elongation (%)
Test kub 0 degree
Tensile zog MPa
Yield point MPa Ntau dua lossis sib npaug
Tus nqi
δ5 Ntau dua lossis sib npaug 22
J Loj dua lossis sib npaug rau 34
σb (470-650)
σs (324-259)
Qhov twg phab ntsa thickness yog nyob nruab nrab ntawm 16-35mm, σs Ntau tshaj los yog sib npaug rau 325Mpa; qhov twg cov phab ntsa thickness nyob nruab nrab ntawm 2. Vuam yam ntxwv ntawm Q345 hlau
2.1 Kev suav ntawm Carbon Equivalent (Ceq)
Ceq=C+Mn/6+Ni/15+Cu/15+Cr/5+Mo/5+V/5
Xam Ceq=0.49%, ntau dua 0.45%, qhia tias qhov weldability ntawm Q345 steel tsis zoo heev, thiab cov txheej txheem nruj yuav tsum tau tsim thaum lub sij hawm vuam.
2.2 Cov teeb meem tshwm sim hauv Vuam Q345 Hlau
2.2.1 Hardening Tendency of the Heat-Teb chaws cuam tshuam
Thaum lub sij hawm txias txheej txheem ntawm vuam Q345 steel, lub tshav kub- cuam tshuam cheeb tsam yog nquag tsim ib tug quenched qauv-martensite, uas ua rau kom lub hardness thiab txo cov yas nyob ze ntawm lub vuam. Qhov no ua rau tom qab -weld tawg.
2.2.2 Txias Cracking Sensitivity
Lub ntsiab vuam tawg hauv Q345 steel yog cov kab nrib pleb txias.
Vuam kev tsim kho
Groove Preparation → Tack Welding → Preheating → Inner Edge Vuam → Back Root Cleaning (Carbon Arc Gouging) → Outer Edge Welding → Inner Edge Vuam → Self-Inspection/Special Inspection → Post-Weld Heat Treatment 2} → Destructive (1) Weld Heat Treatment 2 Tsim nyog)
Kev xaiv cov txheej txheem vuam txheej txheem
Raws li kev txheeb xyuas weldability ntawm Q345 steel, cov kev ntsuas hauv qab no tau tsim:
1. Kev xaiv cov khoom siv vuam
Vim qhov siab nyiam ntawm Q345 steel kom txias tawg, qis - cov khoom siv hydrogen vuam yuav tsum raug xaiv. Xav txog lub hauv paus ntsiab lus uas qhov sib koom ua ke yuav tsum muaj lub zog sib npaug rau lub hauv paus hlau, E5015 (J507) hom vuam electrodes raug xaiv.
Tshuaj muaj pes tsawg leeg yog qhia nyob rau hauv cov lus hauv qab no (%):
Cov ntsiab lus
C
Mn
Si
S
P
Cr
Mo
V
Ti
Cov ntsiab lus
0.071
1.11
0.53
0.009
0.016
0.02
0.01
0.01
0.01
Mechanical zog muaj nyob rau hauv cov lus hauv qab no:
Mechanical Properties Indicators
σb (MPa)
σs (MPa)
δ5 (%)
Ψ (%)
AkvJ-30 degree
Tus nqi
440
540
31
79
164 114 76
(Lub zog tensile yuav tsum ntau dua li lub zog tawm los)
2. Bevel hom: (Muab raws li kos duab thiab khoom siv)
3. Vuam txoj kev: Phau ntawv arc vuam (D).
4. Vuam tam sim no: Kom tsis txhob coarse weld microstructure thiab txo qhov cuam tshuam toughness, me me - nplai vuam tsis yuav tsum tau siv. Cov kev ntsuas tshwj xeeb muaj xws li: siv me me - txoj kab uas hla electrodes, nqaim weld hlaws, nyias weld khaubncaws sab nraud povtseg, thiab ib tug multi- txheej, multi- txheej txheem vuam (welding sequence nyob rau hauv daim duab 1). Qhov dav ntawm weld hlaws yuav tsum tsis txhob ntau tshaj peb zaug ntawm electrode ntev, thiab weld txheej thickness yuav tsum tsis pub tshaj 5 hli. Rau thawj mus rau peb txheej, siv Ф3.2 electrodes nrog vuam tam sim no ntawm 100-130A; rau txheej plaub mus rau thib rau, siv Ф4.0 electrodes nrog vuam tam sim no ntawm 120-180A.
5. Preheating Temperature: Since the Ceq of Q345 steel is >0.45%, preheating yog tsim nyog ua ntej vuam. Lub preheating kub T0=100-150 degree, thiab interpass kub Ti Tsawg tshaj los yog sib npaug rau 400℃.
6. Tshaj tawm- Weld Heat Treatment Parameters: Txhawm rau txo qhov seem vuam kev nyuaj siab, txo cov ntsiab lus hydrogen hauv cov vuam, thiab txhim kho cov vuam microstructure thiab cov khoom, tom qab- vuam cov cua sov yog xav tau. Kev kho cua sov kub yog 600-640 degree, lub sijhawm tuav yog 2 teev (rau lub phaj tuab ntawm 40mm), thiab cua sov / cua txias yog 125℃/ h.
Ntawm -Welding Sequence
1. Preheating Ua ntej Vuam
Ua ntej welding lub flange daim hlau, preheat lawv rau 30 feeb ua ntej pib vuam. Preheating, interpass kub, thiab kev kho cua sov yog txiav txim los ntawm lub tshav kub kho kub tswj txee siv ib tug deb-infrared conveyor siv cua sov rauv. Lub microcomputer cia li teev thiab sau cov cua kub nkhaus, thiab cov thermocouples ntsuas qhov kub. Thaum lub sij hawm preheating, cov ntsiab lus ntsuas thermocouple yog 15mm-20mm deb ntawm ntug bevel.
2. Vuam
2.1 Txhawm rau tiv thaiv vuam deformation, txhua kem sib koom ua ke yog welded symmetrically los ntawm ob tug neeg, nrog rau vuam kev taw qhia ntawm qhov chaw sab nraud. Thaum vuam cov ntug sab hauv (lub bevel nyob ze ntawm lub vev xaib), thawj mus rau peb txheej yuav tsum tau siv me me - nplai kev ua haujlwm, vim qhov no yog qhov tseem ceeb ntawm vuam deformation. Tom qab welding thawj mus rau peb txheej, sab nraub qaum yog ntxuav. Tom qab carbon arc gouging, lub weld yuav tsum tau mechanically hauv av kom tshem tawm qhov chaw carburization, nthuav tawm cov hlau nplaum thiab tiv thaiv cov pa carbonization loj heev uas tuaj yeem ua rau tawg. Sab nrauv weld yuav tsum ua kom tiav nyob rau hauv ib qho dhau los, nrog rau qhov seem sab hauv weld ua tiav kawg.
2.2 Thaum welding txheej thib ob, cov kev taw qhia vuam yuav tsum rov qab mus rau thawj txheej, thiab lwm yam. Txhua qhov sib txuas yuav tsum tau staggered los ntawm 15-20mm.
2.3 Lub vuam tam sim no, vuam ceev, thiab cov txheej txheem vuam yuav tsum zoo ib yam rau ob qho tib si vuam.
2.4 Vuam yuav tsum pib ntawm lub arc- pib phaj thiab xaus rau ntawm arc- phaj kawg. Tom qab welding, txiav tawm lub weld thiab grind nws huv si.
3. Tshaj tawm -weld heat treatment: Weld joint yuav tsum tau ua kom sov-kho tsis pub dhau 12 teev tom qab ua tiav. Yog tias kev kho cua sov tsis tuaj yeem ua tau tam sim ntawd, kev txuag hluav taws xob thiab kev ntsuas cua txias yuav tsum tau ua. Thaum kho cua sov, ob lub thermocouples yuav tsum tau siv los ntsuas qhov kub thiab txias, nrog rau qhov chaw thermocouples -welded rau sab hauv thiab sab nraud ntawm qhov sib txuas.
4. Kev tshuaj xyuas vuam
Raws li qhov yuav tsum tau ua ntawm * Code rau Kev Tsim Kho thiab Kev Txais Cov Qauv Hlau *, kev kuaj ultrasonic tau siv los tshuaj xyuas cov pob qij txha, nrog rau kev soj ntsuam tus nqi ntawm 100%.
Ntawm -Tsev Kawm Ntawv Kev Tswj Xyuas
1. Cov lus qhia ntxaws txog kev ua haujlwm vuam tau npaj.
2. Tag nrho - txheej txheem tswj cov txheej txheem vuam yog qhov tseem ceeb ntawm kev ua kom zoo.
Thaum lub sij hawm vuam ntawm txhua kem sib koom ua ke, ib tus neeg raug xaiv yuav tsum saib xyuas cov txheej txheem vuam. Yog tias tus welder tsis ua raws li cov lus qhia ua haujlwm, vuam yuav tsum tau nres tam sim ntawd. Thaum lub sij hawm vuam txheej txheem, cov neeg ua haujlwm kho cua sov yuav tsum saib xyuas qhov kub ntawm qhov sib cuam tshuam thoob plaws; Yog tias nws dhau tus qauv, tus welder yuav tsum tau ceeb toom tam sim kom tsis txhob vuam.
3. Kev txhim kho kev paub zoo ntawm cov neeg ua haujlwm tsim kho yog qhov tseem ceeb rau kev siv cov txheej txheem vuam.
Ua ntej kev tsim kho, ib qho kev qhia luv luv tau ua rau txhua tus neeg ua haujlwm, thiab daim npav txheej txheem tsim kho tau raug muab. Cov lus qhia luv luv tau piav qhia meej txog cov yam ntxwv ntawm cov txheej txheem vuam thiab qhov tsim nyog thiab cov ntsiab lus tseem ceeb ntawm kev tswj xyuas nruj me ntsis ntawm - qhov chaw vuam txheej txheem.
Xaus
Ua raws li cov txheej txheem vuam no, tag nrho ntawm 102 qhov sib koom ua ke tau welded rau ntawm - qhov chaw, thiab thawj - kis tau tus nqi ntawm qhov tsis yog - qhov kev ntsuas kev puas tsuaj mus txog 100%. Txheeb xyuas los ntawm kev tsim kho tiag tiag, cov txheej txheem vuam no tsis tsuas yog muab rau ntawm - qhov chaw qhia rau vuam Q345 steel, tab sis kuj ua kom cov vuam zoo.
