Yuav ua li cas kom tsis txhob dag Stainless hlau?

Fake stainless hlau tsis yog ib qho teeb meem niche. Nws yog ib qho teeb meem ntau -billion-$ thoob ntiaj teb uas cuam tshuam rau kev tsim kho, kev ua zaub mov, khoom siv kho mob, cov khoom siv hauv hiav txwv, thiab kaum ob ntawm lwm yam lag luam. Raws li tsab ntawv tshaj tawm xyoo 2023 los ntawm Metals Fraud Prevention Initiative, kwv yees li 8-12% ntawmstainless hlau cov khoompauv thoob ntiaj teb tsis ua raws li lawv cov ntawv teev npe tshwj xeeb.

Cov txiaj ntsig muaj xws li kev txhim kho ntxov ntxov thiab cov khoom lag luam tsis ua haujlwm rau kev puas tsuaj ntawm cov qauv kev sib tsoo thiab cov khoom noj khoom haus. Rau tus thawj tswj kev yuav khoom, tus kws tsim khoom, lossis txawm tias tus neeg yuav khoom xav paub, paub yuav ua li cas txheeb xyuas qhov koj tab tom yuav tuaj yeem txuag tau ntau txhiab daus las thiab, qee zaum, muaj sia nyob.

How To Avoid Fake Stainless Steel

Phau ntawv qhia no muab cov lus qhia dav dav, kauj ruam -los ntawm- cov kauj ruam kev kuaj xyuas zoo, txhawb nqa los ntawm cov ntaub ntawv lub hom phiaj thiab kev coj ua zoo tshaj plaws hauv kev lag luam, yog li koj tuaj yeem ntseeg siab txheeb xyuas cov hlau tsis zoo thiab tsis lees txais cov khoom hloov pauv.

Stainless hlau yog hlau -raws li alloy uas muaj qhov tsawg kawg nkaus ntawm 10.5% chromium los ntawm huab hwm coj. Cov chromium reacts nrog oxygen los tsim ib qho passive oxide txheej ntawm qhov chaw, muab stainless hlau nws kos npe corrosion kuj. Cov ntsiab lus ntxiv - feem ntau yog npib tsib xee, molybdenum, manganese, thiab nitrogen - tau ntxiv los txhim kho lub zog, ductility, thiab ua haujlwm rau ib puag ncig tshwj xeeb.

Cov qhab nia uas siv hauv kev lag luam thiab kev lag luam muaj xws li:

Table 1: Hom Stainless Hlau Qib thiab Cov Khoom Tseem Ceeb

Qib	Cr (%)	Tsis muaj (%)	Cov khoom tseem ceeb	Tej kev siv
304	18–20	8–10.5	General corrosion kuj	Chav ua noj, dab dej, khoom noj khoom haus
316	16–18	10–14	Pitting & chloride kuj	Marine, kws, tshuaj
430	16–18	< 0.75	Nruab nrab corrosion kuj	Automotive trim, khoom siv
2205 Duplex	21–23	4.5–6.5	Siab zog + corrosion	Roj & roj, desalination
310S	24–26	19–22	Siab -kub tsis kam	Rauv qhov chaw, tshav kub exchangers

Cov neeg dag ntxias siv tus nqi sib txawv ntawm cov qib. Qib 316 tuaj yeem raug nqi 30-50% ntau dua 304, thiab 304 ntau dua li qis dua - alloy lossis carbon steel. Los ntawm kev hloov cov ntaub ntawv pheej yig dua thiab rov sau lawv dua, cov neeg muag khoom dag ntxias tsim cov txiaj ntsig tsis raug cai loj thaum nthuav tawm qhov kawg - cov neeg siv rau kev pheej hmoo loj.

Ua ntej siv txhua txoj kev sim, tus neeg yuav khoom tau kawm feem ntau tuaj yeem txheeb xyuas cov cim ceeb toom ntawm theem kev lag luam. Cov chij liab hauv qab no yuav tsum ua rau muaj kev tshuaj xyuas tam sim:

Signs of Potentially Fake Stainless Steel

Nqe qis dua tus nqi lag luam: Yog tias tus neeg muag khoom muab 316L ntawm tus nqi tib yam li 304, ib yam dab tsi tsis raug. Siv lub London Hlau Txauv (LME) cov nqi npib tsib xee thiab luam tawm cov nqi ntxiv rau cov nqi ncaj ncees.

Cov ntawv ceeb toom uas ploj lawm lossis tsis sib haum xeeb (MTRs): Cov neeg tsim khoom raug cai ib txwm muab MTRs uas tuaj yeem taug qab rau ib qho tshwj xeeb kub (batch) tooj. MTRs uas tsis muaj tus lej cua sov lossis tsis muaj -tshwj xeeb chemistry yog tus chij liab loj.

Cov ntaub ntawv tsis meej lossis tsis tuaj yeem muaj nyob hauv lub tebchaws: Ntau yam khoom siv dag siv tau los ntawm thaj chaw paub txog kev xa tawm kev dag, nrog cov ntawv pov thawj cuav ntawm keeb kwm.

Tsis pom cov cua sov lossis ntau cov cim rau ntawm cov khoom: Lub tshuab tiag tiag - cov hlau tsis muaj hlau yog stamped lossis laser - cim nrog qib, tus lej kub, thiab tus neeg tsim khoom yog tus kheej.

Ntau dhau polished los yog coated nto: Kev kho deg tuaj yeem zais cov ntaub ntawv tsis zoo, tsis muaj xim, lossis qhov tsis xws luag.

Cov ntawv txheeb xyuas hauv qab no tau muab faib ua tsib theem ntawm kev txheeb xyuas, suav txij li xoom-cov nqi kuaj pom mus rau chav kuaj- tshuaj ntsuam xyuas qib. Siv ntau theem raws li qhov kev pheej hmoo profile thiab pob nyiaj siv ntawm kev yuav khoom.

Thawj kab ntawm kev tiv thaiv yog ua tib zoo saib xyuas thiab kuaj lub cev. Cov tshev no yuav tsum tsis muaj cov cuab yeej thiab yuav tsum tau ua rau txhua qhov khoom xa tuaj.

Table 2: Daim Ntawv Qhia Txog Kev Pom Zoo & Lub Cev

#	Xyuas yam khoom	Dab tsi tiag Steel Shows	Ceeb toom
1	Nto ua kom zoo sib xws	Uniform zeb tiav (2B, BA, Tsis yog. 4, thiab lwm yam) tsis muaj thaj ua rau thaj	Tsis sib xws sheen, blotchy thaj chaw, pom txheej
2	Ntug zoo	Ntxuav, burr - txiav dawb; zoo ib yam thickness	Ragged npoo, txawv thickness nyob rau hauv ib daim ntawv
3	Cov cim & stamps	Qib, Thaum tshav kub kub No., tus tsim lub npe kom meej meej cim	Tsis muaj cov cim, cov cim ploj, lossis tsis sib xws font / qhov sib txawv
4	Ntsuas qhov hnyav	Matches theoretical weight (density: 7,900–8,000 kg/m³)	Qhov tseem ceeb hauv qab - lossis tshaj - nyhav rau qhov ntsuas qhov ntev
5	Dimensional kam rau ua	Tsis pub dhau ASTM A480 lossis EN 10259 kam rau ua	Ntau qhov sib txawv ntawm thickness, dav, los yog flatness

Kev ntsuam xyuas hlau nplaum yog qhov ceev, tus nqi -dawb npo uas siv cov khoom sib nqus ntawm ntau hom hlau. Nws yog ib qho tseem ceeb kom nkag siab txog nws tus nqi thiab nws cov kev txwv ua ntej tso siab rau nws.

Austenitic qib (304, 316, 310) feem ntau tsis yog-magnetic nyob rau hauv lub xeev annealed. Ferritic qib (430, 410) yog cov hlau nplaum zoo heev. Txawm li cas los xij, txias -kev ua haujlwm ntawm qib austenitic tuaj yeem ua rau cov lus teb sib nqus me me - yog li daim ntawv tsis muaj zog sib nqus 304 tsis tuaj yeem ua cuav.

Table 3: Sib nqus teb los ntawm Qib

Qib	Tsev neeg	Sib nqus teb	Txhais lus
304 / 316	Austenitic	Tsis muaj zog heev	Ib txwm yog annealed; me ntsis teb tau txais yog tias txias - ua haujlwm
430 / 410	Ferritic / Martensitic	Muaj zog sib nqus	Kev cia siab thiab ib txwm muaj rau cov qib no
2205	Duplex	Sib nqus sib nqus	Ib txwm; duplex muaj ferrite theem
Cov pa roj carbon steel sau ua SS	N/A	Muaj zog sib nqus	Cov chij liab loj yog muag raws li qib austenitic

Kev Txiav Txim Siab: Cov lus teb muaj zog sib nqus hauv cov khoom muag raws li 304 lossis 316 yog tus chij liab tseem ceeb. Siv cov kev ntsuam xyuas ntxiv kom paub meej.

Cov khoom siv tshuaj tua kab mob yog pheej yig (feem ntau yog $ 30 - $ 80 USD) thiab tuaj yeem yuav los ntawm cov tuam txhab muab khoom siv hlau. Lawv siv cov tshuaj tiv thaiv reagent kom pom qhov muaj lossis tsis muaj cov ntsiab lus tshwj xeeb ntawm cov hlau.

Table 4: Cov Kev Ntsuas Pom Zoo thiab Lawv Lub Hom Phiaj

Xeem lub npe	Element Detected	Kev pom zoo	Siv Case
Molybdenum (Mo) qhov chaw kuaj	Molybdenum	Cov xim txiv kab ntxwv / xim av tsim	Paub qhov txawv 316 (muaj Mo) los ntawm 304 (tsis muaj Mo)
Nickel (Ni) chaw kuaj	Nickel	Paj yeeb / liab xim nrog dimethylgyoxime	Txheeb xyuas Ni muaj nyob hauv qib austenitic
Chromium (Cr) test	Chromium	Daj-txiv kab ntxwv nrog diphenylcarbazide	Paub meej yam tsawg kawg 10.5% Cr cov ntsiab lus hauv chav kawm
Cov pa roj carbon (C) test	Cov ntsiab lus carbon	Xim hloov nrog ferric chloride	Txheeb xyuas qhov siab -carbon (tsis yog-SS) hloov pauv

Kev ntsuam xyuas qhov chaw yog qhov zoo, tsis yog qhov ntau. Lawv lees paub tias muaj ib lub ntsiab lus tshwj xeeb tab sis tsis ntsuas nws qhov feem pua. Rau kev txheeb xyuas qib, lawv yuav tsum tau ua ke nrog ib txoj hauv kev kom muaj nuj nqis.

Portable XRF analyzers - tseem hu ua handheld spectrometers - yog tus qauv kub rau ntawm - qhov chaw pov thawj. Ib lub xov tooj ntawm tes XRF tuaj yeem txheeb xyuas cov ntsiab lus ntawm cov hlau tsis muaj steel hauv 3-15 vib nas this, muab cov tshuaj lom neeg tag nrho piv rau cov txiaj ntsig hauv kev sim.

Table 5: XRF Analysis - Cov Lus Qhia Tseem Ceeb

Parameter	Paub meej
Lub sijhawm ntsuas	3-15 vib nas this rau kev nyeem ntawv
Qhov tseeb	± 0.05-0.1% rau alloying ntsiab (Cr, Ni, Mo)
Cov khoom kuaj pom	Cr, Ni, Mo, Mn, Si, Cu, N, Fe thiab lwm yam
Tus nqi ntaus ntawv	$15,000–$40,000 USD (Xyem muaj los ntawm ~ $500/hnub)
Cov qauv siv tau	ASTM E1476, ISO 14707 Kev Tswj Xyuas Zoo
Kev txwv	Tsis tuaj yeem pom cov teeb pom kev zoo (C, S, P) - lab OES xav tau rau kev tshuaj xyuas tag nrho

Rau kev yuav khoom siab -tus nqi stainless hlau - tshwj xeeb tshaj yog rau kev nyab xeeb- cov ntawv thov tseem ceeb hauv cov roj & roj, aerospace, lossis kev kho mob - XRF xeem yuav tsum suav tias yog qhov yuav tsum tau ua, tsis yog xaiv tau.

Thaum qhov siab tshaj plaws ntawm qhov raug yuav tsum tau ua - piv txwv li, thaum tsim nyog tus neeg xa khoom tshiab lossis tshawb xyuas qhov xav tias kev dag ntxias - cov qauv yuav tsum raug xa mus rau qhov chaw kuaj hlau uas tau lees paub rau Optical Emission Spectrometry (OES) lossis Inductively Coupled Plasma (ICP) tsom xam.

Cov txheej txheem no xa cov ntawv pov thawj, raug cai tiv thaiv cov txiaj ntsig uas suav nrog txhua yam cuam tshuam rau kev txheeb xyuas qib, suav nrog carbon, sulfur, thiab phosphorus uas XRF tsis tuaj yeem ntseeg tau. Kev soj ntsuam hauv chav kuaj feem ntau raug nqi $ 50 - $ 300 USD rau ib qho qauv thiab siv sijhawm 1-5 hnub ua haujlwm.

Kev kuaj lub cev ib leeg tsis txaus. Cov txheej txheem ua tiav kev pov hwm zoo yuav tsum suav nrog kev txheeb xyuas cov ntaub ntawv nruj. Cov ntaub ntawv hauv qab no yuav tsum tau thov thiab txheeb xyuas rau txhua qhov tseem ceeb ntawm stainless hlau yuav:

Table 6: Daim ntawv teev cov ntaub ntawv xav tau

	Cov ntaub ntawv	Yuav Qhia Li Cas	Standard Reference
1	Mill Test Report (MTR / EN 10204 3.1 lossis 3.2)	Thaum tshav kub kub No., chemistry, mechanical props, producer name, certification	EN 10204, ASTM A480
2	Daim ntawv pov thawj ntawm Conformance (CoC)	Qib, tus qauv, qhov ntev, kom muaj nuj nqis sib tw yuav xaj raws nraim	ISO 9001 / AS9100
3	Lub teb chaws ntawm Keeb Kwm Daim Ntawv Pov Thawj	Sib tw shipping cov ntaub ntawv thiab cov khoom tshaj tawm	WTO cov cai ntawm keeb kwm
4	Thib peb-Txoj Kev Tshawb Fawb Kev Tshawb Fawb	Cov ntaub ntawv pov thawj ntawm tus neeg soj ntsuam, XRF lossis OES cov txiaj ntsig, hnub tim thiab qhov chaw kuaj xyuas	ISO / IEC 17025 Kev Tswj Xyuas Kev Lag Luam
5	RoHS / REACH Ua Raws Cai	Tsis muaj cov khoom txwv; xav tau rau EU kev lag luam nkag	EU Cov Lus Qhia 2011/65/EU

Hla- hais txog tus naj npawb cua sov ntawm MTR nrog tus lej xov tooj cua sov lub cev ntaus cim rau ntawm cov khoom. Qhov no ib kauj ruam catches ib tug loj feem ntawm cov ntaub ntawv dag.

Siv daim ntawv teev cov ntsiab lus nram qab no raws li kev siv ceev ceev ua ntej ua tiav kev yuav khoom stainless hlau lossis txais kev xa khoom. Txhua yam khoom yuav tsum raug kuaj xyuas tsuas yog thaum paub tseeb tias txaus siab.

Table 7: Master Quality Check Summary Checklist

	Daim ntawv teev npe	Tier	Ua ntej
1	Txheeb xyuas tus nqi vs. kev ua lag luam benchmark (LME + alloy surcharge)	Kev lag luam	Siab
2	Tshawb xyuas qhov chaw tiav thiab cov cim pom pom	Lub cev	Siab
3	Tshawb xyuas qhov hnyav piv rau qhov ntsuas qhov ntsuas	Lub cev	Siab
4	Ua qhov ntsuas hlau nplaum (qib austenitic yuav tsum tsis yog - lossis tsis muaj zog hlau nplaum)	Lub cev	Nruab nrab
5	Thov thiab txheeb xyuas MTR nrog tus lej xov tooj cua sov ntawm cov khoom	Cov ntaub ntawv	Tseem ceeb
6	Thov Certificate of Conformance matching purchase order details	Cov ntaub ntawv	Tseem ceeb
7	Ua tshuaj ntsuam xyuas qhov chaw (Mo test rau 316 vs. 304)	Tshuaj	Siab
8	Ua XRF tsom xam ntawm cov qauv neeg sawv cev	Tshuaj	Siab
9	Txheeb xyuas lub teb chaws ntawm cov ntaub ntawv keeb kwm	Cov ntaub ntawv	Nruab nrab
10	Commission tau lees paub lab OES / ICP rau cov neeg xa khoom tshiab lossis cov ntawv thov tseem ceeb	Laboratory	Siab

Yog tias koj cov txheej txheem pov thawj ua rau muaj kev txhawj xeeb loj, ua raws li cov kauj ruam no:

Fake Stainless Steel

Quarantine cov khoom xa tuaj tam sim. Tsis txhob ua, txiav, lossis faib cov khoom xav tias tseem tab tom tshawb nrhiav.

Commission ywj siab kuaj xyuas. Lub chaw kuaj ISO/IEC 17025-kev lees paub tsim cov ntaub ntawv pov thawj raug cai.

Sau ntawv ceeb toom rau koj tus neeg muag khoom. Sau tag nrho cov kev sib txuas lus. Thov ib daim ntawv piav qhia nrog cov ntaub ntawv pov thawj.

Qhia rau cov tub ceev xwm cuam tshuam. Hauv Tebchaws Meskas, hu rau US International Trade Commission (USITC) lossis Department of Commerce's Enforcement and Compliance division. Hauv EU, tiv tauj lub koom haum kev lis kev cai hauv tebchaws.

Koom nrog kws lij choj. Cov khoom siv dag zog tuaj yeem ua rau muaj kev cog lus kho mob, thov kev tuav pov hwm, lossis kev xa mus ua txhaum cai nyob ntawm txoj cai lij choj.

Cov hlau tsis zoo yog qhov tseeb, raug nqi, thiab qee zaum teeb meem txaus ntshai. Qhov xwm zoo yog tias nws kuj tseem tiv thaiv tau ntau. Los ntawm kev sib koom ua lag luam ceev faj, tshuaj xyuas lub cev, tshuaj ntsuam xyuas tshuaj, thiab kev txheeb xyuas cov ntaub ntawv nruj, cov neeg yuav khoom ntawm txhua qib - los ntawm cov neeg lag luam loj loj mus rau cov neeg cog lus me - tuaj yeem txo lawv qhov cuam tshuam rau cov khoom cuav.

Lub hauv paus ntsiab lus tseem ceeb yog kev txheeb xyuas txheej txheej. Tsis muaj ib qho kev xeem yog foolproof. Cov khoom siv tuaj yeem dhau qhov kev xeem hlau nplaum thiab tseem yog qib tsis raug. Ib qho MTR tuaj yeem yog qhov tseeb tab sis muaj qhov sib txawv ntawm cov cua sov dua li cov khoom uas nws nrog. Kev siv ntau txoj hauv kev ntxiv los kaw cov qhov khoob no.

Kev nqis peev hauv cov cuab yeej pov thawj thiab cov txheej txheem tsim nyog rau koj qib kev pheej hmoo. Rau - cov khoom lag luam muaj nqis qis, kev tshuaj xyuas qhov muag thiab cov ntaub ntawv txheeb xyuas yuav txaus txaus. Rau kev nyab xeeb - tseem ceeb lossis siab - daim ntawv thov muaj txiaj ntsig, XRF tsom xam thiab thib peb- kev tshuaj xyuas tog tsis yog xaiv tau ntxiv - lawv yog qhov tseem ceeb rau kev mob siab rau.

Yog lawm. Qib 304 tuaj yeem pom qhov staining los yog pitting hauv cov tshuaj chloride ntau heev -ib puag ncig nplua nuj (xws li dej hiav txwv, de- icing ntsev). Qhov no tsis tas txhais tau tias nws yog cuav - nws tsuas yog qib tsis raug rau daim ntawv thov. Qib 316, uas muaj molybdenum, yog qhov ua tau zoo dua rau cov tshuaj chloride{10}}induced corrosion.

Q: Puas yog hlau nplaum hlau nplaum ib txwm cuav?

Tsis yog. Ferritic thiab martensitic qib (430, 410, 17-4 PH) yog cov hlau nplaum sib nqus thiab raug cai tag nrho. Txawm tias qib austenitic zoo li 304 tuaj yeem dhau los ua cov hlau nplaum me ntsis tom qab ua haujlwm txias. Cov ntsiab lus thiab qib kev qhia tshwj xeeb yog qhov tseem ceeb thaum txhais cov ntawv xeem hlau nplaum.

Q: Kuv yuav ua li cas thiaj nrhiav tau lub chaw soj ntsuam kev lees paub?

Tshawb nrhiav cov npe ntawm koj lub teb chaws lees paub lub cev: A2LA (USA), UKAS (UK), DAkkS (Lub Tebchaws Yelemees), lossis CNAS (Tuam Tshoj). Xyuas kom lub chaw soj nstuam tuav ISO / IEC 17025 kev lees paub rau kev kuaj hlau thiab tuaj yeem muab daim ntawv tshaj tawm kev xeem nrog kev ntsuas tsis paub tseeb.

Q: Dab tsi yog qhov feem ntau ntawm cov hlau tsis muaj kev dag ntxias?

Kev dag ntau tshaj plaws yog kev hloov qib qib - muag 430 lossis qis dua - cov khoom siv qib 304, lossis 304 li 316. nto plating ntawm carbon steel lossis qis- alloy steel los ua kom zoo li cov hlau tsis muaj steel kuj tau sau tseg, tshwj xeeb tshaj yog nyob rau hauv cov neeg siv khoom- qib khoom.