cov khoom siv stainless hlau 17-4

MIM 17-4 PH Overview

Raws li AISI 17-4 PH tus qauv, MIM 17-4 PH yog martensitic nag lossis daus-hardening stainless hlau. Nws yog qhov txawv los ntawm kev sib xyaw ntawm corrosion kuj thiab mechanical zoo.

Ib qho ntawm feem ntau siv MIM cov ntaub ntawv hauv cov hlau txhaj tshuaj molding sector yog 17-4 PH stainless hlau. Cov hlau no muaj kev sib xyaw zoo ntawm corrosion kuj, hardness, thiab lub zog. Cov khoom nyuaj nrog lub zog zoo yog ua tau los ntawm 17-4 qhov tshwj xeeb zoo. Tsis tas li ntawd, kev sib zog ua haujlwm thib ob yog ua tiav thaum lub sijhawm sintering los ntawm kev hloov kho qee yam tsis muaj.

Txij li thaum 17-4 PH resists corrosion zoo ib yam li 304L, nws yog nquag siv nyob rau hauv daim ntawv thov uas yuav tsum tau txhua yam khoom.

Tsis tas li ntawd, MIM-17-4 PH tau txheeb xyuas los ntawm UNS S17400, AISI 630, ASTM A564, AMS 5643, thiab stainless hlau 17-4 PH.

 

Kev sib xyaw ntawm Tshuaj

Cov tshuaj muaj pes tsawg leeg ntawm Stainless Steel 17-4 yog teev hauv qab no, nrog cov ntsiab lus thiab lawv qhov hnyav feem pua:

• Hlau (Fe):Balance (qhov seem)
• Nickel (Ni):3.00-5.00%
• Silicon (Si):1.00%
• Cov pa roj carbon (C):0.07%
• Chromium (Cr):15.50-17.50%
• Niobium (Nb):0.15-0.45%
• Manganese (Mn):1.00%
• Copper (Cu):3.00-5.00%
• Sulfur (S):0.03%

Cov muaj pes tsawg leeg ua kom cov khoom muaj zog, corrosion kuj, thiab lwm yam khoom tsim nyog rau ntau yam kev siv.

MIM 17-4 PH stainless hlau feem ntau muaj cov khoom siv zoo uas yog 10-25% phem tshaj wrought 17-4 PH. Cov laj thawj tseem ceeb suav nrog:

Sintering flaws muaj xws li lingering carbon impurities, khaws cia pores, thiab nplej.
Evaporation-induced poob ntawm cov ntsiab lus: Cr, Cu, thiab Ni.
impurity suav nrog: O, C, thiab N.

Nrog qeeb sintering, lub ntsej muag-centered cubic austenite theem yog stabilized los ntawm carbon thiab nitrogen Cheebtsam. Ntawm qhov tod tes, lub cev-centered cubic delta ferrite yuav nrawm nrawm ntawm sintering. Stainless hlau 17-4PH dhau los nag lossis daus cov tshuaj tiv thaiv uas ua rau muaj zog hardness thiab lub zog, qhov seem delta-ferrite txo lub zog. Tsis tas li ntawd, martensite tshwm sim thaum lub caij txias tom qab sintering.

Ib qho tseem ceeb ntawm MIM cov khoom yog oxygen. Thawj qhov chaw ntawm cov hmoov hlau tsis muaj hlau coated nrog oxides yog siab, thiab cov pa oxygen txawv nyob ntawm cov hmoov tsim. Cov pa oxygen siab hauv MIM 17-4 PH qhov chaw ua rau tsis zoo corrosion kuj thiab cov yam ntxwv tsis zoo vim tias cov oxides no yuav tshem tawm chromium lub peev xwm los tiv thaiv corrosion.

 

Cov Khoom Zoo

Cov txheej txheem sophisticated rau tsim intricate, high-kev ua tau zoo stainless hlau qhov chaw yog MIM. Peak kub, cua sov tus nqi, ib puag ncig, tuav ntev, thiab hmoov particle loj tag nrho cuam tshuam li cas stainless hlau 17-4 PH sinters. Ntau yam cuam tshuam rau qhov muaj pes tsawg leeg ntawm 17-4 PH alloy, uas nyob rau hauv lem cuam tshuam lub microstructure theem, sintering tus cwj pwm, thiab cov yam ntxwv kawg. Nitrogen los ntawm cov txheej txheem cua, oxygen los ntawm cov hmoov los yog cua, thiab carbon los ntawm cov hmoov los yog binder yog lub hauv paus Cheebtsam.

 

Qhov zoo tshaj plaws sib npaug ntawm lub zog, hardness, thiab corrosion kuj ua rau 17-4 PH yog ib qho kev xaiv nrov. Cov khoom lag luam hauv cov khoom siv hluav taws xob, kev kho hniav, tshuaj, thiab aerospace pom qhov sib xyaw ntawm cov khoom zoo txaus siab tom qab kev kho cua sov. sib txawv raws li qhov muaj pes tsawg leeg, nrog kev hloov pauv hauv Fe, Ni, Cu, thiab Cr. Qhov kub ntawm solidus yog nyob ib ncig ntawm 1405 ° C, thiab cov kua dej yog kwv yees li 1440 ° C. Cov khoom zoo yog teb rau kev kho cua sov; Kev puas tsuaj elongation yog li ntawm 8 mus rau 14%, lub zog tawm los ntawm 760 txog 1240 MPa, tensile lub zog ntawm 1000 txog 1340 MPa, thiab hardness ncav cuag 43 HRC.

 

Qhov tshwj xeeb sib xyaw ua ke ntawm lub zog, hardness, thiab corrosion kuj ua rau 17-4 PH stainless hlau yog ib qho kev xaiv hauv kev lag luam hlau txhaj tshuaj molding. Martensitic stainless hlau uas feem ntau nag lossis daus hardened yog 17-4 PH.

• Lub zog loj
• Nyuaj heev
• Zoo heev tiv thaiv corrosion
• Toughness rau pob txha
• yam ntxwv ntawm kev kho cua sov thiab vuam

 

Cov teebmeem ntawm Binder thiab Debinding

Rau cov hlau tsis muaj steel 17-4 PH txhaj tshuaj molding, ntau lub tshuab binder siv; Qhov nrov tshaj plaws yog 60% muab tub lim, 30% qaum qaum, thiab 10% surfactant.

Vim tias cov khoom xyaw uas tseem tshuav yuav hloov pauv cov pa oxygen lossis cov pa roj carbon kawg, kev debinding muaj feem cuam tshuam rau cov yam ntxwv kawg. De-polymerization los yog hnyav extraction yog thawj kauj ruam hauv kev debinding; Piv txwv li, paraffin wax dissolves nyob rau hauv heptane, thiab polythylene glycol dissolves nyob rau hauv dej kub. Ntxiv mus, fuming nitric acid yog siv rau hauv catalytic debinding kom tshem tawm polyoxymethylene. Txoj hauv kev zoo tshaj plaws los tshem tawm cov ntawv khi hauv theem thib ob ntawm kev debinding yog tuav nws ntawm 600 txog 1000 ° C hauv ib puag ncig hydrogen. Cov theem no qee zaum hu ua sintering pib theem.

 

Sintering Parameter cuam tshuam

Ib tug xov tooj ntawm cov variables sib cuam tshuam thaum lub sij hawm sintering ntawm stainless hlau 17-4 PH los txhais qhov kawg ceev, theem, microstructure, thiab cov yam ntxwv. Plaub yam tseem ceeb ntawm kev txheeb xyuas kev txheeb xyuas yog kev kho cua sov, sintering cua, pib oxygen concentration, thiab particle loj.

Qhov kub ntawm sintering muaj feem cuam tshuam rau sintered ntom.

 

Qhov loj ntawm cov khoom

Nto diffusion yog txheej txheem los ntawm thawj cov khoom sib txuas thaum lub sij hawm sintering; ib qho me me nrog thaj tsam loj dua yuav ntxiv dag zog rau thawj daim ntawv cog lus. Cov pob txha pob txha polymer cov particle adhesion yuav raug hloov los ntawm qhov chaw diffusion bonding ib zaug binder pyrolysis tshwm sim. Grain ciam diffusion xav tau caj dab loj hlob raws li sintering bonding ntawm hlau hais nce thiaj li tsim tau grain ciam ntawm hais. Thaum cov ntaub ntawv ciam teb, cov nplej loj ua lub luag haujlwm tseem ceeb hauv sintering thaum pib shrinkage, thiab nws muaj qhov cuam tshuam rov qab rau tus nqi sintering. Txawm li cas los xij, qhov cuam tshuam ntawm qhov loj me me tuaj yeem cuam tshuam los ntawm qhov kub thiab txias ntau dua lossis lub sijhawm tuav ntev dua.

 

Cov huab cua

Nyob rau hauv stainless hlau, tus qauv sintering ib puag ncig xaiv muaj xws li lub tshuab nqus tsev, hydrogen, nitrogen, hydrogen-nitrogen, thiab argon-hydrogen.


Ob qhov nrov tshaj plaws sintering cua rau stainless hlau 17-4 PH yog hydrogen thiab lub tshuab nqus tsev. Thaum muaj cov pa roj carbon monoxide ntxiv, muaj qhov pom tseeb poob hauv oxide. Ob leeg silicon thiab chromium tuaj yeem tuav mus rau oxygen yam tsis muaj carbon ntxiv ntawm graphite. Kev txo qis oxidation tshwm sim thaum qhov kub thiab txias thiab qib hydrogen siab; qhov qis qis qis yuav lav qhov txheej txheem no. Qhov txias saum npoo oxidation uas tshwm sim tom qab sintering yuav tsim ib tug passive txheej ntawm silicon, hlau, thiab chromium uas resists corrosion.

Raws li ib tug muaj zog austenite stabilizer, nitrogen muaj feem xyuam rau txoj kev loj hlob ntawm martensite thiab cov yam ntxwv kawg ntawm stainless hlau. Thaum nws txias, nitrogen, uas yog soluble hauv austenite, precipitates li Cr2N. Cov chromium nyob rau hauv thaj tsam ntawm cov qoob loo yuav depleted los ntawm no precipitate, uas yuav ua rau lub zos corrosion tshwm sim sai heev. Raws li qhov tshwm sim, peb yuav tsum tiv thaiv nitrogen los ntawm kev nkag mus rau hauv qhov chaw sintering thiab txias cov khoom hauv qab 900 ° C ntawm qhov nrawm ntawm 200 ° C ib feeb. nyob rau hauv stainless hlau 17-4 PH los tiv thaiv zus tau tej cov chromium nitride.

Graphite kuj tseem ua rau qis ib feem ntawm cov pa roj carbon monoxide nyob rau hauv lub tshuab nqus tsev vacuum, uas yog vim li cas graphite lub tshuab nqus tsev furnaces muaj kev vam meej nyob rau hauv lub tshuab nqus tsev sintering. Ntawm 1300 ° C thiab qis CO ib feem siab ntawm 0.001, nws tuaj yeem hloov chromium oxide rau chromium.

 

 

Kub thiab cua sov tus nqi

Cov sintering cycles xws li impurity tshem tawm thiab cov txheej txheem binder burnout uas entail cua sov thiab tuav ntawm ntau yam kub. Rau kev txo qis impurity, qhov zoo tshaj plaws kub yog ze rau 1000 ° C, thaum rau qhov kawg polymer tshem tawm, nws yog ze rau 600 ° C.

Stainless hlau 17-4PH raug sintering shrinkage nyob rau hauv dilatometry kuaj ntawm lub ncov tus nqi ntawm txog 1250 ° C, whereas puv-density (98%) yuav tsum tau ib tug ncov kub ntawm 1300 ° C. Tooj thiab chromium yuav, txawm li cas los xij, evaporate ntawm qhov kub siab no, tej zaum ua rau poob ntawm kev kho cua sov thiab kev tiv thaiv corrosion.

 

Tsis tas li ntawd, cov synthesis ntawm delta-ferrite yog pab los ntawm kub ntau dua; los ntawm kev nthuav dav sai, theem no yuav pab tau qhov kawg densification. Dawb delta-ferrite cov cheeb tsam thiab thaj chaw tsaus ntawm lub voj voog oxide pores pom nyob rau hauv cov duab hauv qab no micro-structure ntawm MIM 17-4PH hauv sintering.

Microstructure ntawm 1260 SS17-4 MIM

 

Tswj cov pa roj carbon

Thaum lub sij hawm sintering txheej txheem, carbon yog lwm austenite stabilizer. Lub zog thiab hardness siab dua yuav ua tiav nrog cov ntsiab lus qis qis hauv 17-4, qis dua 0.1 feem pua. Stainless hlau 17-4 PH's theem, densification, thiab cov yam ntxwv ntawm txhua yam yuav raug cuam tshuam los ntawm cov pa roj carbon ntsiab lus hloov.

 

Cov txheej txheem MIM cov hmoov atomized, binder residues, debinding voj voog, sintering ib puag ncig, pib oxygen, thiab peak sintering kub yog qee qhov kev hloov pauv uas cuam tshuam rau qib carbon. Thawj qhov kev txiav txim siab ntawm qhov kawg ntawm cov ntsiab lus carbon thaum sintering yog thawj qib oxygen. Piv txwv li, 0.03% carbon yog ploj thaum lub sij hawm hydrogen sintering ntawm 17-4 roj atomized hmoov ntawm 1343 ° C. Tsis tas li ntawd, tshwj xeeb tshaj yog nyob rau qis sintering kub, binder residues tuaj yeem ua rau cov pa roj carbon monoxide.

Hauv hydrogen thiab nqus sintering, lub zog tensile ntawm stainless hlau 17-4 yog cuam tshuam los ntawm cov nyiaj ntawm cov pa roj carbon monoxide. Nyob rau hauv ob qho tib si H900 los yog H1100 kev kho cua sov, los yog nyob rau hauv tus qauv sintering ntawm 1300 mus rau 1360 ° C. Cov duab hauv qab no qhia txog yuav ua li cas lub zog tensile noticeably txo qis thaum cov ntsiab lus carbon nce.

 

Kev tuav lub sij hawm

Hauv sintering, tuav lub sij hawm ntawm qhov kub siab tshaj plaws poob ntawm 60 thiab 120 feeb. los ntawm sintered density piv rau qhov kub thiab txias thiab lub sij hawm daim duab raws li nram no. Raws li qhov kub thiab txias nce ntawm 1240 ° C mus rau 1360 ° C, nws qhia tau hais tias qhov ceev ceev ntawm 96.3% mus rau 98.3%. Cov sintering compacts ua tiav qhov ntom ntom (98%), tom qab 60 feeb ntawm tuav. Porosity raug tshem tawm thiab tus nqi ntawm pore annihilation yog txo thaum lub sijhawm no. Qhov poob ntawm cov ciam teb nplej thiab porosity qaug zog yog thawj qhov ua rau.

 

Cov txiaj ntsig ntawm MIM 17-4

Siab tiv taus corrosion
Thaum tshav kub kub kev kho mob-vim lub hnub nyoog hardening
Muaj zog thiab durability
Tawm tsis kam mus rau tshav kub
Zoo tagnrho rau MIM cov geometry nyuaj

 

Mechanical yam ntxwv

Raws li cov khoom siv, MIM 17-4 PH yog siv. Cov yam ntxwv uas nyiam sib piv yog lub zog, hardness, thiab elongation. Tsis tas li ntawd, qaug zog, tawm dag zog, thiab tawg toughness yog cov teeb meem uas cuam tshuam los ntawm ntau qhov kev hloov pauv.

Cov duab hauv qab no qhia txog qhov nruab nrab ntawm 17-4 PH raws li kev txheeb xyuas kev txheeb xyuas ntawm ntau qhov haujlwm MIM. Sintering tsis yog lub luag hauj lwm rau ib ncig ntawm 60% ntawm variation nyob rau hauv cov khoom.

 

Raws li MIM kev lag luam tus qauv, stainless hlau 17-4 PH yuav tsum muaj lub zog tensile yam tsawg kawg nkaus ntawm 790 MPa, hardness ntawm 27 HRC tom qab sintering, thiab hardness ntawm 1070 MPa thiab 33 HRC tom qab kho cua sov. 4% elongation rau ob leeg. Lub zog tensile ntawm stainless hlau 17-4PH tom qab 1350 ° C sintering thiab H900 kho cua sov yog 1280 MPa rau roj-atomized hmoov thiab 1136 MPa rau dej-atomized hmoov. Nws yuav tsum raug sau tseg tias roj atomized hmoov tuaj yeem ua tiav lub zog tensile ntawm 1485 MPa nrog 9% elongation.

 

Kev tiv thaiv corrosion

Plaub hom sintered stainless hlau (304, 316, 430, thiab 17-4) raug rau cov qauv kev kuaj corrosion nyob rau hauv ntau yam xwm txheej. Cov txiaj ntsig tau pom tias 17-4 yog qhov tsawg tshaj plaws tiv thaiv cov mob no. Tsis tas li ntawd, vim cov pores ntawm sintered Cheebtsam ua rau lub zos corrosion los ntawm concentration polarization, wrought cov ntaub ntawv yog ntau resistant rau corrosion tshaj sintered khoom. Hydrogen sintering thiab roj atomized hmoov yog ob txoj kev nrov los txhim kho corrosion vim tias cov pa oxygen seem yog qhov tsis zoo.

Corrosion kuj tseem cuam tshuam nrog biocompatibility. Thaum piv rau titanium thiab cobalt alloys, stainless hlau 17-4 PH muaj cytotoxicity zoo tab sis tsis muaj kev sib tw tag nrho biocompatibility.

 

PH Daim Ntawv Thov Kev Lag Luam rau MIM 17-4

Cov khoom zoo tshaj plaws yog muab los ntawm 17-4 PH stainless hlau ntawm qhov kub thiab txias li 350 ° C. Tsis tas li ntawd, nws yog ruaj txaus rau ob lub vase hlau thiab welds, thiab warping thiab scaling yuav txo tau los ntawm cua sov ntawm ib tug tsawg kub rau ib lub sij hawm luv luv.

Vim tias nws zoo dua corrosion thiab kub tsis kam, aerospace 17-4 stainless hlau yog qhov kev xaiv zoo rau kev siv dav hlau. Cov hmoov purity siab thiab densification tuaj yeem ua kom lub neej ntawm MIM 17-4 cov khoom thiab txo qhov kev hloov pauv.

Tsheb
Cov khoom siv dav tshaj plaws hauv kev tsim tsheb yog stainless hlau 17-4 vim nws yooj yim rau kev ua ntau yam duab. Nrog rau kev ua tau zoo heev, hlau txhaj tshuaj molding tshuab kuj ua rau nws muaj peev xwm rau txoj kev geometry.

Cov neeg muas zaub
Vim nws qhov tshwj xeeb corrosion kuj, 17-4 yog dav siv hauv cov neeg siv khoom siv siv MIM technology. Tsis tas li ntawd, qhov tshwj xeeb lub zog thiab hardness ntawm cov khoom no lav kev ua haujlwm tsis raug yuam kev.

Hauv kev xaus

MIM 17-4 PH ua rau kev ua haujlwm zoo hauv kev ua kom zoo ntawm cov khoom siv. Rau ntau daim ntawv thov tsim nyog, nws muaj ntau yam kev txaus siab ua ke ntawm sintered zog. Sintering kub yog qhov tseem ceeb ntawm kev txiav txim siab zaum kawg thaum piv rau hom hmoov, particle loj, ntsuab ntom, tuav ntev, thiab lwm yam tsis. Tsis tas li ntawd, cov theem uas muaj nyob rau hauv cov ntaub ntawv sintered cuam tshuam rau sintered zog.

Lub sijhawm no, kev kho cua sov tom qab sintering, sintered ntom, thiab theem morphology tag nrho cuam tshuam cov yam ntxwv. Thaum sintered ntom txiav cov yam ntxwv, Kub Isostatic Pressing (HIP) txhim kho lawv.

Hlau Txhaj Moulding (MIM) tau nce siab ntxiv nrog stainless hlau 17-4 PH. Txhawm rau muab cov ntawv thov ntxiv rau sintered 17-4 PH, JHMIM nyob ntawm MIM technology puag.