Duplex treatment of plasma nitriding and manganese phosphating of 42CrMo4 steel for corrosion resistance increasing

Kód výsledku v IS VaVaI

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Nalezeny alternativní kódy

RIV/00216305:26220/17:PU136113

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Duplex treatment of plasma nitriding and manganese phosphating of 42CrMo4 steel for corrosion resistance increasing

Popis výsledku v původním jazyce

Plasma nitriding is widely used as a final operation to improve wear, fatigue and corrosion resistance of industrial parts. Nevertheless, corrosion resistance can be further increased by post-oxidizing or by manganese phosphate conversion coating. This paper considers the duplex treatment of plasma nitriding and manganese phosphating of 42CrMo4 steel surface, widely used for manufacturing of breech mechanism in the armament production. Plasma nitriding was carried out at 500 °C for 15 h in different nitriding atmosphere having hydrogen and nitrogen gas flow ratio with 3 to 1 (l/h) and of 1 to 3 (l/h). Plasma nitrided steel samples were manganese phosphated (without lubrication). The treated samples were characterized using metallographic techniques, microhardness, and NSS corrosion tests. Different compound layer thickness under different nitriding gas ratio was confirmed. The X-ray diffraction analysis (XRD) confirmed different volumes of ε-Fe2-3N, γ'-Fe4N nitrides in the compound layers and hureaulite Mn5 (PO3 (OH))2 (PO4)2 (H2O)4 in the manganese phosphate coatings. The visual and gravimetric evaluation was carried out and corrosion rates modified to weight gains were calculated for corrosion evaluation. After removing of corrosion products weight losses were measured and pitting factors were calculated. Duplex treatment (manganese phosphating after plasma nitriding) also displayed increased corrosion resistance and suppressed pitting propagation in comparison with the plasma nitrided steel samples and a potential to further increase of corrosion resistance of plasma nitrided structural steels.

Název v anglickém jazyce

Duplex treatment of plasma nitriding and manganese phosphating of 42CrMo4 steel for corrosion resistance increasing

Popis výsledku anglicky

Plasma nitriding is widely used as a final operation to improve wear, fatigue and corrosion resistance of industrial parts. Nevertheless, corrosion resistance can be further increased by post-oxidizing or by manganese phosphate conversion coating. This paper considers the duplex treatment of plasma nitriding and manganese phosphating of 42CrMo4 steel surface, widely used for manufacturing of breech mechanism in the armament production. Plasma nitriding was carried out at 500 °C for 15 h in different nitriding atmosphere having hydrogen and nitrogen gas flow ratio with 3 to 1 (l/h) and of 1 to 3 (l/h). Plasma nitrided steel samples were manganese phosphated (without lubrication). The treated samples were characterized using metallographic techniques, microhardness, and NSS corrosion tests. Different compound layer thickness under different nitriding gas ratio was confirmed. The X-ray diffraction analysis (XRD) confirmed different volumes of ε-Fe2-3N, γ'-Fe4N nitrides in the compound layers and hureaulite Mn5 (PO3 (OH))2 (PO4)2 (H2O)4 in the manganese phosphate coatings. The visual and gravimetric evaluation was carried out and corrosion rates modified to weight gains were calculated for corrosion evaluation. After removing of corrosion products weight losses were measured and pitting factors were calculated. Duplex treatment (manganese phosphating after plasma nitriding) also displayed increased corrosion resistance and suppressed pitting propagation in comparison with the plasma nitrided steel samples and a potential to further increase of corrosion resistance of plasma nitrided structural steels.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20501 - Materials engineering

Projekt

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Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

METAL 2017 - 26TH ANNIVERSARY INTERNATIONAL CONFERENCE ON METALLURGY AND MATERIALS

ISBN

978-808729479-6

ISSN

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e-ISSN

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Počet stran výsledku

7

Strana od-do

1077-1084

Název nakladatele

TANGER Ltd

Místo vydání

Brno, Czech Republic

Místo konání akce

Brno

Datum konání akce

24. 5. 2017

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

000434346900172