Cov ntaub ntawv technical
2. AISI 4340 Steel Specification thiab cov qauv tsim nyog
| Lub teb chaws |
Teb chaws USA |
Tebchaws Askiv |
Tebchaws Askiv |
Nyiv |
| Txuj |
ASTM A29 |
TS EN 10250 |
SIB 970 |
JIS G4103 |
| Qib |
4340 |
36CrNiMo4/
1.6511 |
EN24/817M40 |
NWS 439/SNCM8 |
3. ASTM 4340 Steels Thiab Equilvalents Chemical Composition
| Txuj |
Qib |
C |
Mn |
P |
S |
Si |
Ni |
Cr |
Mo |
| ASTM A29 |
4340 |
0.38-0.43 |
0.60-0.80 |
0.035 |
0.040 |
0.15-0.35 |
1.65-2.00 |
0.70-0.90 |
0.20-0.30 |
| TS EN 10250 |
36CrNiMo4/
1.6511 |
0.32-0.40 |
0.50-0.80 |
0.035 |
0.035 |
≦0.40 |
0.90-1.20 |
0.90-1.2 |
0.15-0.30 |
| SIB 970 |
EN24/817M40 |
0.36-0.44 |
0.45-0.70 |
0.035 |
0.040 |
0.1-0.40 |
1.3-1.7 |
1.00-1.40 |
0.20-0.35 |
| JIS G4103 |
NWS 439/SNCM8 |
0.36-0.43 |
0.60-0.90 |
0.030 |
0.030 |
0.15-0.35 |
1.60-2.00 |
0.60-1.00 |
0.15-0.30 |
4. AISI Alloy 4340 Steel Mechanical Properties
| Mechanical Properties
(Kub kho mob)
|
Qhov xwm txheej |
Tshooj cai
mm |
Tensile zog MPa |
Yield zog
MPa |
Elong.
% |
Izod Impact
J |
Brinell
Hardness |
| T |
250 |
850-1000 |
635 |
13 |
40 |
248-302 |
| T |
150 |
850-1000 |
665 |
13 |
54 |
248-302 |
| U |
100 |
930-1080 |
740 |
12 |
47 |
269-331 |
|
| V |
63 |
1000-1150 |
835 |
12 |
47 |
293-352 |
| W |
30 |
1080-1230 |
925 |
11 |
41 |
311-375 |
| X |
30 |
1150-1300 |
1005 |
10 |
34 |
341-401 |
|
| Y |
30 |
1230-1380 |
1080 |
10 |
24 |
363-429 |
| Z |
30 |
1555- |
1125 |
5 |
10 |
444- |
Thermal Properties
| Cov khoom |
Metric |
Imperial |
| Thermal expansion co-efficient (20 ° C / 68 ° F, piv txwv roj hardened, 600 ° C (1110 ° F) temper |
12.3 µm/m°C |
6.83 µin/in° F |
| Thermal conductivity (tseem steel) |
44.5 W/mK |
309 BTU in/hr.ft².°F |
5. Forging ntawm 4340 Alloy Steel
Preheat cov hlau 4340 ua ntej, kub txog li 1150 ° C - 1200 ° C siab tshaj plaws rau forging, tuav kom txog thaum kub tsis sib xws thoob plaws hauv seem.
Tsis txhob ua kom qis dua 850 ° C. 4340 muaj cov yam ntxwv zoo forging tab sis kev saib xyuas yuav tsum tau ua thaum txias vim tias cov hlau pom tias muaj kev cuam tshuam rau kev tawg. Tom qab kev ua haujlwm forging, cov khoom ua haujlwm yuav tsum tau txias kom qeeb li sai tau. Thiab cua txias hauv cov xuab zeb lossis cov txiv qaub qhuav yog pom zoo thiab lwm yam.
6. AISI 4340 Steel Qib Kev kho cua sov
Rau pre-hardened steel kev nyuaj siab relieving yog tiav los ntawm cua sov steel 4340 mus rau ntawm 500 mus rau 550 ° C. Tshav kub rau 600 ° C - 650 ° C, tuav kom txog thaum qhov kub tsis sib xws thoob plaws hauv seem, tsau rau 1 teev ntawm 25 mm seem, thiab txias hauv huab cua.
Ib qho kev sib tw tag nrho tuaj yeem ua tiav ntawm 844 ° C (1550 F) ua raws li kev tswj hwm (lub qhov cub) txias ntawm tus nqi tsis ceev tshaj 10 ° C (50 F) ib teev mus rau 315 ° C (600 F). Los ntawm 315 ° C 600 F nws yuav yog cua txias.
AISI 4340 alloy steel yuav tsum nyob rau hauv lub tshav kub kho los yog normalized thiab kub kho mob ua ntej tempering. Lub tempering kub yog nyob ntawm lub zog theem xav tau. Rau qib siab zog hauv 260 - 280 ksi kub kub ntawm 232 ° C (450 F). Rau lub zog ntawm 125 - 200 ksi temper ntawm 510 ° C (950 F). Thiab tsis txhob npau taws rau 4340 steels yog tias nws yog nyob rau hauv 220 - 260 ksi lub zog ntau yam li tempering tuaj yeem ua rau degradation ntawm kev cuam tshuam rau qib ntawm lub zog no.
Tempering yuav tsum tau zam yog tias ua tau nyob rau hauv thaj tsam 250 ° C - 450 ° C vim temper brittleness.
- Nplaim lossis Induction Hardening
Raws li tau hais los saum no, pre-hardened thiab tempered 4340 steel tuav los yog daim hlau tuaj yeem ua rau saum npoo tawv ntxiv los ntawm cov nplaim taws lossis induction hardening txoj kev uas ua rau cov ntaub ntawv hardness ntau tshaj Rc 50. AISI 4340 steel qhov chaw yuav tsum tau rhuab kom sai li sai tau. Qhov kub ntawm austenitic (830 ° C - 860 ° C) thiab qhov yuav tsum tau muaj qhov tob ua raws li cov roj los yog dej quenching tam sim ntawd, nyob ntawm seb qhov hardness yuav tsum tau, workpiece loj / zoo li thiab quenching kev npaj.
Tom qab quenching rau tes sov, tempering ntawm 150 ° C - 200 ° C yuav txo cov kev ntxhov siab nyob rau hauv cov ntaub ntawv nrog tsawg heev rau nws hardness.
Tag nrho cov khoom de-carburised nto yuav tsum tau muab tshem tawm ua ntej kom ntseeg tau tias qhov zoo tshaj plaws.
Hardened thiab tempered 4340 alloy steel kuj tuaj yeem ua nitrided, muab qhov chaw hardness txog Rc 60. Thaum tshav kub kub txog 500 ° C - 530 ° C thiab tuav lub sijhawm txaus (los ntawm 10 mus rau 60 teev) los tsim qhov tob ntawm rooj plaub. Nitriding yuav tsum tau ua raws li kev ua kom txias qeeb (tsis muaj quench) txo qhov teeb meem ntawm distortion. Cov nitrided qib 4340 cov ntaub ntawv tuaj yeem raug machined kom ze rau qhov kawg loj, tawm hauv kev sib tsoo me me xwb. Lub zog tensile ntawm 4340 steel cov khoom siv feem ntau tsis cuam tshuam vim qhov kub ntawm nitriding feem ntau qis dua qhov qub tempering kub ua haujlwm.
Deg hardness ua tiav yog 600 txog 650HV.
7. Machinability
Machining yog ua tau zoo tshaj plaws nrog cov hlau alloy 4340 nyob rau hauv lub annealed los yog normalized thiab tempered mob. Nws tuaj yeem ua tau yooj yim los ntawm txhua txoj hauv kev xws li sawing, tig, drilling thiab lwm yam. Txawm li cas los xij, nyob rau hauv lub zog siab ntawm 200 ksi lossis ntau dua lub machinability tsuas yog los ntawm 25% mus rau 10% ntawm cov hlau nyob rau hauv cov mob annealed.
8. Vuam
Vuam ntawm steel 4340 nyob rau hauv lub hardened thiab tempered mob (raws li ib txwm muab), yog tsis pom zoo thiab yuav tsum tau zam yog hais tias txhua yam ua tau, vim hais tias ntawm qhov txaus ntshai ntawm quench cracking, raws li cov neeg kho tshuab zog yuav hloov nyob rau hauv lub weld tshav kub cuam tshuam cheeb tsam.
Yog tias vuam yuav tsum tau ua, ua ntej kub rau 200 txog 300 ° C thiab tswj qhov no thaum vuam. Tam sim ntawd tom qab vuam kev ntxhov siab txo qis ntawm 550 txog 650 ° C, ua ntej hardening thiab tempering.
Yog hais tias vuam nyob rau hauv lub hardened thiab tempered mob yog tiag tiag tsim nyog, ces qhov chaw ua hauj lwm piece, tam sim ntawd ntawm txias rau tes sov so, yuav tsum tau yog hais tias ua tau kom muaj kev ntxhov siab relieved ntawm 15 ° C hauv qab no tempering kub.
9. Daim ntawv thov ntawm 4340 Hlau
AISI 4340 steel yog siv nyob rau hauv feem ntau kev lag luam sectors rau daim ntawv thov uas yuav tsum tau siab tensile / tawm lub zog tshaj 4140 steel yuav muab tau.
Qee yam kev siv xws li:
- Aircraft tsaws iav
- Automotive,
- Roj thiab Roj Drilling,
- Forging,
- Ua kom sov thiab txias,
- Tshuab Tsev,
- Hloov Cov Txheej Txheem, zoo li lub zog xa hluav taws xob thiab cov ncej.
- General engineering industries thiab structural siv daim ntaub ntawv, xws li: hnyav luag hauj lwm shafts, zog, axles, spindles, couplings, pins, chucks, pwm thiab lwm yam.
Gnee Steel yog ib qho ntawm cov khoom lag luam ntawm AISI 4340 steel rau koj daim ntawv thov sib txawv raws li saum toj no. Thiab peb muab 4140 steel, 4130 steels thiab. Hu rau kuv thiab qhia rau kuv paub koj qhov kev thov txhua lub sijhawm.
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