440B stainless hlau phaj

Qib 440B stainless hlau yog tempered ntawm 148℃(300℃F) kom tau cov khoom siab tshaj plaws thiab qhov siab tshaj plaws hardness uas tuaj yeem tau txais yog RC 58.

 

Q1: Tus qauv specification thiab tshuaj muaj pes tsawg leeg ntawm 440B stainless hlau yog dab tsi?

A1: 440B yog martensitic stainless hlau txhais los ntawm cov qauv xws li AISI, ASTM A276, thiab UNS S44003. Nws cov tshuaj muaj pes tsawg leeg (wt%) yog: Carbon (C) 0.75-0.95, Chromium (Cr) 16.00-18.00, Molybdenum (Mo) 0.75-1.25, Manganese (Mn) Tsawg dua lossis sib npaug li 1.00, Silicon (Si) Phoess Less than 0 los yog sib npaug rau 0. 0.040, Sulfur (S) Tsawg dua lossis sib npaug 0.030, thiab Nickel (Ni) Tsawg dua lossis sib npaug rau 0.60. Qhov sib npaug ntawm cov pa roj carbon thiab chromium cov ntsiab lus ua rau muaj kev sib txuam ntawm hardness thiab corrosion kuj.

 

Q2: Dab tsi yog cov khoom tseem ceeb ntawm 440B stainless hlau tom qab kev kho cua sov kom zoo?

A2: Thaum raug quenching (1010-1070 degree, roj / cua txias) thiab tempering (150-300℃rau siab hardness los yog 400-600℃rau enhanced toughness), 440B exhibits zoo heev mechanical kev ua tau zoo: Lub zog tensile Ntau tshaj los yog sib npaug rau 1750 MPa dua, yield zog ntau dua tshaj los yog sib npaug rau 6%, txo qhov cheeb tsam loj dua los yog sib npaug rau 30%, thiab Hardness (HRC) Ntau dua los yog sib npaug rau 58. Nws ua tau zoo tshaj 440A hauv kev hnav tsis kam thaum tuav zoo toughness dua 440C.

 

Q3: Hauv qhov xwm txheej twg yog 440B stainless hlau feem ntau siv?

A3: 440B yog qhov zoo tagnrho rau cov ntawv thov uas yuav tsum muaj qhov sib npaug ntawm kev hnav tsis kam, kev tiv thaiv corrosion, thiab tawv, suav nrog: Nruab nrab-load bearings, valve stems thiab rooj zaum, twj twj tso kua mis, lub zog thiab pinions, cov cuab yeej txiav (xws li, cov cuab yeej ua haujlwm ntoo), cov cuab yeej phais, marine hardware, thiab cov khoom siv tshuab ua haujlwm hauv ib puag ncig corrosive.

 

Q4: Yuav ua li cas 440B stainless hlau piv rau 440A thiab 440C nyob rau hauv cov nqe lus ntawm kev ua tau zoo thiab daim ntawv thov haum?

A4: Qhov sib txawv tseem ceeb yog nyob rau hauv cov ntsiab lus carbon, uas tsav hardness thiab hnav tsis kam:

440A (C: 0.60-0.75): Cov ntsiab lus qis tshaj plaws → zoo tshaj plaws toughness thiab weldability, tab sis qis tshaj hardness (HRC ~ 55 max) → haum rau cov ntaub ntawv tsis tseem ceeb.

440B (C: 0.75-0.95): Sib npaug cov ntsiab lus carbon → nruab nrab hardness (HRC ~ 58 max), zoo toughness, thiab zoo hnav tsis kam tshaj 440A → zoo tagnrho rau dav dav -lub hom phiaj siab hnav cov khoom.

440C (C: 0.95-1.20): Cov ntsiab lus carbon siab tshaj plaws → siab tshaj plaws hardness (HRC Ntau dua lossis sib npaug li 60) thiab hnav tsis kam, tab sis txo qhov tawv thiab weldability → haum rau huab cua - hnav, qis- toughness-requirement scenarios.

 

Q5: Dab tsi yog qhov tseem ceeb rau kev kho cua sov, kev ua haujlwm, thiab kev tiv thaiv corrosion ntawm 440B stainless hlau?

A5: - Kev kho cua sov: Tsis txhob tempering ntawm 475-550℃los tiv thaiv "475℃embrittlement" (poob ntawm toughness). Rau siab tshaj plaws hardness, temper ntawm 150-300 degree; rau kev txhim kho ductility, temper ntawm 400-600 degree.