Qhov tseem ceeb ntawm Surface Hardening rau siab -Speed Steel
High -Speed steel (HSS) yog siv dav hauv kev tsim cov cuab yeej txiav, tuag, thiab cov khoom siv tshuab vim nws cov tawv tawv zoo heev, tawv, thiab hnav tsis kam. Txawm li cas los xij, nyob rau hauv cov kev pab cuam hnyav heev -xws li siab - txiav ceev, rov cuam tshuam, thiab kev sib txhuam- HSS cov khoom yog feem ntau hnav, oxidation, thiab qaug zog tsis ua hauj lwm, txwv lawv lub neej kev pab cuam. Laser hardening, raws li ib tug precision nto tshav kub kev kho mob technology, tau tshwm sim raws li ib tug zoo txoj kev los txhim kho qhov nto ntawm HSS. Los ntawm hauv zos cua sov HSS nto mus rau austenitizing kub nrog ib tug tsom laser beam thiab cia siab rau lub ceev ceev kub conduction ntawm lub substrate rau nws tus kheej -quenching, nws ua ib tug siab -hardness martensitic txheej yam tsis muaj kev cuam tshuam rau tej yam khoom siv. Tshawb nrhiav cov txiaj ntsig ntawm laser hardening ntawm cov khoom saum npoo ntawm HSS yog qhov tseem ceeb rau kev ua kom zoo ntawm cov txheej txheem, txhim kho kev ntseeg siab ntawm cov khoom, thiab nthuav dav daim ntawv thov ntawm HSS hauv siab -xav tau kev lag luam.
Qhov cuam tshuam rau Surface Hardness thiab hnav tsis kam
Laser hardening ho txhim kho qhov tawv tawv thiab hnav tsis kam ntawm siab -ceev steel. Raws li cov txheej txheem kev pom zoo (laser zog 1-5 kW, scanning ceev 1-5 m / min), qhov nyuaj ntawm HSS (xws li W6Mo5Cr4V2) tuaj yeem ncav cuag 65-70 HRC, uas yog 10-15% siab dua li cov kev kho cua sov ib txwm muaj. Qhov no yog vim qhov tsim ntawm nplua{17}}grained martensite thiab khaws cia cov pa roj carbon supersaturated nyob rau hauv martensitic lattice thaum lub sij hawm laser cua sov thiab quenching. Cov qauv martensitic ntom ntom txo cov yas deformation ntawm qhov chaw nyob rau hauv kev sib txhuam, thaum lub zog carbides (piv txwv li, MC, M6C) precipitated thaum tempering ntxiv txhim khu kev hnav tsis kam. Hnav cov kev ntsuam xyuas qhia tau hais tias laser- hardened HSS txiav cov cuab yeej muaj lub neej kev pab 2-3 zaug ntev dua cov unhardened, nrog rau cov hnav mechanism hloov los ntawm cov nplaum hnav mus rau ib tug me me abrasive hnav, zoo txo cov khoom poob thaum lub sij hawm kev pab cuam.
Qhov cuam tshuam rau Surface Microstructure
The surface microstructure of high-speed steel undergoes significant transformation after laser hardening. Before hardening, HSS typically consists of pearlite, ferrite, and coarse carbides. During laser hardening, the rapid heating (heating rate up to 104–105 °C/s) causes the pearlite and ferrite to quickly transform into austenite, while the coarse carbides partially dissolve into the austenite. The subsequent rapid quenching (cooling rate >103℃/ s) inhibits qhov diffusion ntawm carbon atoms, ua rau tsim cov nplua acicular martensite es tsis txhob coarse martensite tsim nyob rau hauv ib txwm kub kho. Tsis tas li ntawd, cov carbides undissolved nplua yog uniformly faib nyob rau hauv martensitic matrix, ua raws li "reinforcement phases" los cuam tshuam lub zog ntawm dislocations. Lub tshav kub- cuam tshuam cheeb tsam (HAZ) ntawm laser- hardened HSS yog nqaim (tsuas yog 0.5-2 hli), thiab cov microstructure hloov tau yooj yim los ntawm cov txheej txheem hardened mus rau lub hauv paus cov ntaub ntawv, tsis txhob muaj cov yam ntxwv tsis xws luag xws li cov kab nrib pleb thiab xyuas kom meej cov khoom ntawm cov khoom.
Qhov cuam tshuam rau Deg Residual Stress thiab Fatigue Performance
Laser hardening qhia txog compressive residual kev nyuaj siab nyob rau saum npoo ntawm high -ceev steel, uas muaj txiaj ntsig zoo rau kev txhim kho kev qaug zog. Cov cua kub ceev thiab cua txias thaum lub sij hawm tus txheej txheem ua rau thermal expansion thiab contraction sib txawv ntawm cov txheej saum npoo thiab cov substrate: txheej txheej nthuav thaum rhuab thiab yog constrained los ntawm txias substrate, generating compressive kev nyuaj siab tom qab txias. Qhov loj ntawm qhov chaw compressive residual kev ntxhov siab tuaj yeem ncav cuag -300 txog -600 MPa, uas cuam tshuam qhov tensile stress generated thaum lub sij hawm kev pab cuam, txo qhov pib thiab propagation ntawm qaug zog tawg. Kev ntsuam xyuas qaug zog qhia tau tias cov khoom siv laser-hardened HSS muaj qhov kev qaug zog nce los ntawm 20-30% piv rau cov tsis muaj zog. Txawm li cas los xij, cov txheej txheem tsis raug (piv txwv li, lub zog laser ntau dhau, qeeb qeeb scanning ceev) tuaj yeem ua rau muaj kev ntxhov siab ntau dhau, ua rau muaj kev ntxhov siab nyob hauv tensile los yog cov kab nrib pleb, uas cuam tshuam rau kev ua haujlwm tsis zoo. Yog li, txheej txheem optimization yog ib qho tseem ceeb los xyuas kom meej qhov zoo ntawm residual stress distribution.
Xaus: Kev Ntsuas Kev Ntsuas thiab Kev Pom Zoo rau yav tom ntej
Laser hardening muaj txiaj ntsig zoo thiab muaj txiaj ntsig zoo rau cov khoom saum npoo ntawm siab -cov hlau nrawm, ua tiav kev txhim kho qhov tawv tawv, hnav tsis kam, thiab kev ua haujlwm qaug zog los ntawm kev tswj cov txheej txheem saum npoo av thiab qhia cov kev ntxhov siab seem. Nws kov yeej cov kev txwv ntawm kev kho cua sov ib txwm muaj (xws li HAZ loj, qhov tsis sib xws) thiab muab txoj hauv kev meej, muaj txiaj ntsig zoo los txhim kho cov kev pabcuam kev ua haujlwm ntawm HSS Cheebtsam. Cov kev tshawb fawb yav tom ntej yuav tsum tsom mus rau kev ua kom zoo ntawm cov txheej txheem laser hardening tsis haum rau ntau hom HSS (xws li hmoov metallurgy HSS) thiab sib txuas laser hardening nrog rau lwm cov kev hloov kho saum npoo av (xws li, PVD txheej, nitriding) kom ua tiav kev sib koom ua ke ntawm cov khoom nto. Nrog rau kev txhim kho ntawm cov tshuab laser ntse, tiag tiag- lub sijhawm saib xyuas thiab kev hloov kho ntawm cov txheej txheem hardening yuav ntxiv txhim kho qhov ruaj khov ntawm cov cuab yeej saum npoo av, txhawb kev siv dav dua ntawm laser- hardened HSS nyob rau hauv siab -kawg manufacturing teb.
