Kev tshuaj xyuas qhov zoo ntawm Manganese ntawm Machinability ntawm Carbon Steel

Txawm hais tias manganese tsis yog ib qho tseem ceeb alloying hauv carbon steel, nws cov nyhuv ntawm optimizing cov khoom siv machinability yog qhov tseem ceeb. Machinability tseem ceeb ntsuas cov khoom muaj peev xwm ua tiav qhov siab - qhov ntev thiab qhov zoo ntawm qhov chaw zoo thaum lub sij hawm machining txheej txheem xws li txiav, drilling, thiab milling, thaum tib lub sij hawm txo cov cuab yeej hnav thiab siv zog. Manganese txhim kho lub machinability ntawm carbon steel los ntawm ntau qhov ntev los ntawm kev hloov nws cov microstructure, mechanical zog, thiab physicochemical lub xeev thaum txiav, tshwj xeeb tshaj yog nyob rau hauv cov nram qab no plaub yam tseem ceeb:

 

 

I. Grain Refinement thiab txo qhov txiav tsis kam

 

Manganese muaj cov txiaj ntsig tseem ceeb hauv kev ua kom zoo ntawm cov hlau. Ntawm ib sab, manganese tuaj yeem cuam tshuam kev loj hlob ntawm austenite nplej thaum cua sov, tshwj xeeb tshaj yog nyob rau hauv cov txheej txheem pretreatment xws li normalizing thiab annealing, txhawb kev tsim cov nplua thiab zoo ferrite -pearlite qauv. Ntawm qhov tod tes, raws li cov carbide muaj zog- tsim cov khoom, manganese ua ke nrog cov pa roj carbon hauv cov hlau los tsim Mn₃C carbides zoo. Cov carbides yog dispersed nyob rau hauv lub matrix, ntxiv hindering grain coarsening.

 

Qhov txiaj ntsig ncaj qha ntawm kev nplua - cov qauv nplej rau cov txheej txheem txiav yog nyob rau hauv kev txo cov kev ua haujlwm siab: thaum lub cuab yeej txiav cov pa roj carbon steel, cov nplej ua kom zoo ntxiv cov qoob loo ntawm cov khoom siv. Lub atomic bonding rog ntawm cov ciam teb yog qhov tsis muaj zog, ua rau nws yooj yim dua rau cov cuab yeej los rhuav tshem cov atomic bonds hauv cov khoom, yog li txo qhov "khoom deformation resistance" thaum lub sij hawm txiav. Qhov tseeb machining cov ntaub ntawv qhia tau hais tias nyob rau hauv 45Mn carbon steel nrog ib tug manganese ntsiab lus ntawm 0.8% -1.2%, lub txiav quab yuam yog txo los ntawm kwv yees li 15% -20% piv rau cov ntshiab ferritic carbon hlau tsis muaj manganese. Qhov no yog tshwj xeeb tshaj yog pom nyob rau hauv qis-ceev txiav scenarios (xws li drilling thiab tapping), txo cov cuab yeej cuab tam load, txo qhov kev pheej hmoo ntawm workpiece deformation vim yog heev txiav quab yuam, thiab kev txhim kho machining seem raug.

 

II. Txhim kho cov khoom yas thiab txo cov nti tawg

 

Thaum lub sij hawm txiav cov txheej txheem ntawm carbon steel, "chip morphology" ncaj qha cuam tshuam rau machining stability thiab deg zoo: yog hais tias cov khoom ntawm plasticity tsis zoo, "chipping" yog yooj yim generated thaum txiav, uas tsis tsuas yog khawb lub workpiece nto tab sis kuj yuav ua rau lub cuab tam tawg vim muaj kev co; Yog hais tias lub plasticity siab dhau lawm, "ribbon-zoo li chips" tau yooj yim tsim, qhwv ib ncig ntawm lub cuab yeej lossis workpiece, cuam tshuam rau kev ua haujlwm txuas ntxiv.

Manganese tuaj yeem ua kom zoo dua nti morphology los ntawm kev tswj cov yas ntau yam ntawm cov hlau. Ntawm qhov tod tes, manganese tuaj yeem yaj hauv ferrite, txhim kho nws cov plasticity thiab toughness, yog li tiv thaiv cov khoom los ntawm kev tawg vim ntau dhau brittleness thaum txiav. Ntawm qhov tod tes, Mn₃C carbide tsim los ntawm manganese thiab carbon muaj qhov hardness qis dua Fe₃C (cementite) thiab kev faib tawm ntau dua, txo qhov cuam tshuam ntawm cov khoom nyuaj ntawm cov cuab yeej txiav. Nws kuj ua rau cov chips los ua "segmented chips" thaum puas lawm -chip morphology uas tsis txhob entanglement nyob rau hauv lub workpiece thiab xyuas kom meej smoothness ntawm cov txheej txheem txiav. Piv txwv li, nyob rau hauv machining 20Mn carbon steel nrog ib tug manganese ntsiab lus ntawm 0.5% -0.8%, qhov kev faib ua feem ntawm segmented chips yuav ncav cuag tshaj 80%, kev txhim kho lub machining stability ntawm kwv yees li 30% piv rau dog dig 20 # carbon steel (muaj 0.3% -0.6% manganese).

 

III. Txhim kho Nto Zoo thiab txo qhov tsis xws ntawm qhov chaw

 

Qhov saum npoo zoo ntawm cov khoom siv tshuab (xws li nto roughness Ra, qhov nyuaj ntawm qhov chaw, thiab kev ntxhov siab seem) yog qhov tseem ceeb rau kev ntsuas kev ua haujlwm ntawm machining. Manganese ho txhim kho qhov zoo ntawm qhov chaw los ntawm kev hloov kho qhov txiav deformation thiab kev sib txhuam ntawm cov pa roj carbon steel. Los ntawm kev pom ntawm qhov chaw roughness tswj, manganese refines lub grain loj, txhim kho cov uniformity ntawm yas deformation thaum txiav thiab tiv thaiv nto tearing los yog burrs los ntawm coarse nplej. Piv txwv li, hauv milling, tus nqi Ra ntawm 65Mn carbon steel nrog cov ntsiab lus manganese ntawm 1.0%-1.3% tuaj yeem tswj tau ruaj khov ntawm 1.6-3.2 μm, thaum Ra tus nqi ntawm carbon steel ntawm tib lub zog tsis muaj manganese feem ntau tshaj 6.3 μm. Tsis tas li ntawd, manganese tuaj yeem txo qhov coefficient ntawm kev sib txhuam ntawm cov pa roj carbon steel thiab cov cuab yeej txiav (xws li siab- ceev steel thiab cemented carbide): lub xub ntiag ntawm Mn₃C carbides txo qhov kev sib cuag ncaj qha ntawm lub cuab yeej rake lub ntsej muag thiab cov chips, txo cov kev sib txhuam thaum tshav kub kub thiab tiv thaiv nto oxidation los yog cov cuab yeej ua kom tsis zoo-kev kub ceev tshwj xeeb tshaj yog los ntawm kev kub ceev. (xws li Raws li milling speeds> 100 m / min), txo qhov tshwm sim ntawm microcracks nto.

Los ntawm qhov kev xav ntawm cov khoom siv kho tshuab saum npoo av, manganese txhim kho kev ua haujlwm hardening peev txheej ntawm cov hlau: Thaum lub sij hawm txiav, txheej txheej hardened yog tsim rau ntawm cov khoom nto vim yas deformation. Cov txheej tawv tawv no feem ntau yog 5-10 μm tuab, thiab nws qhov tawv tawv yog 20% ​​-30% siab dua li cov substrate. Cov txheej tawv tawv no txhim kho qhov hnav tsis kam thiab qaug zog ua haujlwm ntawm qhov chaw ua haujlwm, ua rau nws tsim tshwj xeeb rau cov khoom siv kho tshuab uas xav tau kev pabcuam txuas ntxiv (xws li shafts thiab gears), txo qhov kev xav tau ntxiv rau kev kho qhov chaw ntxiv dag zog tom qab machining.

 

IV. Extending Tool Lub neej thiab txo tus nqi Machining

 

Cov cuab yeej lub neej yog qhov tseem ceeb cuam tshuam rau kev lag luam machining, thiab manganese txuas ntxiv lub neej ntawm cov cuab yeej los ntawm kev txo cov cuab yeej hnav thiab txo kev puas tsuaj los ntawm kev txiav cov cua sov.

Ntawm qhov tod tes, manganese txo qis kev hnav ntawm cov cuab yeej txiav: Fe₃C cementite hauv cov pa roj carbon zoo tib yam muaj qhov nyuaj siab (kwv yees li 800 HV) thiab nyiam muab faib rau hauv daim ntawv blocky, ua rau "sib tsoo" cuam tshuam ntawm lub cuab yeej ntug thaum txiav, ua kom cov cuab yeej siv nrawm dua. Mn₃C carbides, ntawm qhov tod tes, muaj qhov nyuaj ntawm kwv yees li 600-700 HV thiab muab faib ua kom zoo, sib cais, txo qhov cuam tshuam thiab kev sib tsoo ntawm lub cuab yeej. Cov kev ntsuam xyuas tiag tiag qhia tau tias thaum machining 45Mn carbon steel nrog cov ntsiab lus manganese ntawm 0.8%, lub neej ntawm cov cuab yeej carbide txuas ntxiv los ntawm kwv yees li 25% -35% piv rau kev ua haujlwm zoo tib yam 45 # carbon steel (muaj 0.4% manganese).

Ntawm qhov tod tes, manganese txo cov thermochemical hnav ntawm cov cuab yeej txiav: Cov hluav taws xob sib txhuam tsim thaum txiav ua rau lub cuab yeej kub siab (txog 800-1000℃). Thaum qhov kub thiab txias, cov khoom siv (xws li WC-Co carbide) yog cov tshuaj lom neeg cov tshuaj tiv thaiv nrog cov ntsiab lus hauv carbon hlau (xws li oxidation ntawm Co thiab decomposition ntawm WC). Manganese tuaj yeem tsim cov yeeb yaj kiab MnO oxide nyias ntawm lub ntsej muag rake ntawm cov cuab yeej txiav. Cov oxide zaj duab xis no muaj cov nyhuv lubricating, txo cov khoom diffusion ntawm qhov kub thiab txias thiab txo cov thermochemical coj tus nqi ntawm cov cuab yeej. Piv txwv li, thaum tig, thaum machining 50Mn carbon steel nrog cov ntsiab lus ntawm manganese ntawm 1.0%, cov thermal hnav tus nqi ntawm cov cuab yeej raug txo los ntawm li 20% piv rau machining zoo tib yam 50 # carbon steel, uas ua rau cov cuab yeej tsis tshua muaj kev hloov thiab indirectly txhim kho machining efficiency.

 

Summary: Synergistic Optimization Value of Manganese

 

Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias cov txiaj ntsig zoo ntawm manganese ntawm kev ua haujlwm ntawm cov pa roj carbon steel tsis raug cais tawm tab sis zoo sib xws nrog cov ntsiab lus carbon thiab kev kho cua sov. Piv txwv li, nyob rau hauv qis- carbon hlau (C < 0.25%), manganese feem ntau txhim kho cov yas kom zoo dua nti morphology; nyob rau hauv nruab nrab - carbon steel (0.25% < C < 0.6%), manganese sib npaug txiav tsis kam thiab nto zoo los ntawm refining nplej thiab regulating carbide faib; thiab hauv siab -carbon steel (C> 0.6%), manganese feem ntau txo cov cuab yeej siv los ntawm kev txo cov carbide hardness.

Zuag qhia tag nrho, rationally tswj cov manganese cov ntsiab lus nyob rau hauv carbon steel (feem ntau nyob rau hauv qhov ntau ntawm 0.3%-1.5%) tuaj yeem txhim kho kev ua haujlwm ntawm plaub qhov loj me: txiav quab yuam, nti morphology, nto zoo, thiab lub neej cuab yeej. Qhov no ua kom ob qho tib si machining raug thiab ua haujlwm tau zoo thaum txo cov nqi tsim khoom, ua rau nws txoj hauv kev tseem ceeb rau kev ua kom zoo dua qub hauv cov khoom siv carbon steel.