CORROSION RESISTANCE OF PLASMA NITRIDED AND MANGANESE PHOSPHATED 42CRMO4 STEEL

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60162694%3AG43__%2F17%3A00534909" target="_blank" >RIV/60162694:G43__/17:00534909 - isvavai.cz</a>

Result on the web

—

DOI - Digital Object Identifier

—

Result language

čeština

Original language name

CORROSION RESISTANCE OF PLASMA NITRIDED AND MANGANESE PHOSPHATED 42CRMO4 STEEL

Original language description

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)2·4(H2O) 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.

Czech name

CORROSION RESISTANCE OF PLASMA NITRIDED AND MANGANESE PHOSPHATED 42CRMO4 STEEL

Czech description

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)2·4(H2O) 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.

Type

D - Article in proceedings

CEP classification

—

OECD FORD branch

20501 - Materials engineering

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

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

Article name in the collection

Vrstvy a povlaky 2017

ISBN

978-80-972133-2-9

ISSN

—

e-ISSN

—

Number of pages

6

Pages from-to

—

Publisher name

Liss a.s.

Place of publication

Trenčianská Teplá

Event location

Rožnov pod Radhoštěm

Event date

Oct 23, 2017

Type of event by nationality

EUR - Evropská akce

UT code for WoS article

—