1. Cov khoom sib xyaw & cov khoom tseem ceeb
Q:Dab tsi txhais cov tshuaj / txhua yam khoom ntawm 25CrMo4?
A:
Chemical (wt%):
C: 0.22–0.29 | Cr: 0.90–1.20 | Mo: 0.15–0.30 | Mn: 0.60–0.90 | P/S:Tsawg dua lossis sib npaug li 0.025.
Mechanical:
Yield zog (sᵧ):Ntau tshaj lossis sib npaug rau 550 MPa |Tensile (sₜ):700-900 MPa.
Elongation (A₅):Ntau dua lossis sib npaug li 14% |Kev cuam tshuam (KV):Ntau tshaj lossis sib npaug rau 40J ntawm -20 degree.
Nco tseg:25CrMo4 yog aCr-Mo alloy steelnrog zoo heev qaug zog thiab weldability (Ceq Tsawg dua los yog sib npaug rau 0.47).
2. Kev tsim khoom & qauv ua raws
Q:Yuav ua li cas yog 25CrMo4 raj tsim thiab ntawv pov thawj?
A:
Txheej txheem:Feem ntauseamless(kub-kub + txias-kos); welded variants xav tau tag nrho normalization.
Kev kho cua sov:Q&T yuav tsum tau (Quenching ntawm 880-920℃+ Tempering ntawm 550-650 degree).
Standard Scope:EN 10297-1 rau cov ntawv thov kub / siab (piv txwv li, boilers).
3. Dimensional Tolerances
Q:Dab tsi kam rau ua rau 25CrMo4 raj?
A:
| Parameter | Ua siab ntev | Kev thuam |
|---|---|---|
| OD | ± 0.8% (min ± 0.4 hli) | Xyuas kom nias- haum qhov tseeb |
| Phab ntsa Thickness | ± 8% (min ± 0.4 hli) | Tseem ceeb heev rau creep resistance |
| Kev ncaj | Tsawg dua lossis sib npaug li 1.2 mm / m | Tseem ceeb heev rau siab -siab tshuab |
4. Daim Ntawv Thov & Kev Txwv
Q:25CrMo4 feem ntau siv nyob qhov twg?
A:
Siab -Tsub:Fais fab nroj tsuag boilers (tsawg dua los yog sib npaug li 550 degree), kub exchangers.
Roj & Roj:Laum dab tshos, riser systems (Q&T variants).
Zam:
Temperatures >600℃(kev pheej hmoo ntawm carbide nag lossis daus).
Sour service (H₂S) tsis muaj ISO 15156-raws li PWHT.
5. Kev lees paub zoo & ntawv pov thawj
Q:Yuav ua li cas thiaj paub tseeb?
A:
Yuav tsum xeem:
Tensile (EN ISO 6892-1)|Kev cuam tshuam (ISO 148-1 ntawm -20 degree).
NDT:100% ultrasonic (EN 10246-1) + hardness mapping.
Cov ntawv pov thawj:EN 10204 3.2|PED 2014/68/EU (Qeb IV).
