The gas corrosion of the cobalt base clad layer at elevated temperature

• Autorzy: Smolenska H.
• Języki publikacji: EN

Abstrakty

EN

Purpose: Purpose of this paper is to evaluate the microstructural and mechanical properties evolution of the laser and PTA clad layers made of the powder containing cobalt after oxidation in air (750°C, 200 hours) and corrosion in exhaust gases (700°C, two month). Design/methodology/approach: The layers were made by cladding technique. Cladding was conducted with a high power diode laser HDPL ROFIN SINAR DL 020 and Plasma Transformed Arc method. The subsequent tracks were overlapped by 30÷40%. The performance of the hardfaced materials were evaluated by microstructure (optical and scanning electron microscope SEM), chemical analysis and micro hardness measurements. Findings: After heat treatment the microstructure of the clad layers did not change much, neither on the top part nor in the clad/steel interface. However the oxide layer on the surface is observed. The EDS analyze revile the composition of this scale which consisted generally of chromium and iron oxides. The semi-quantitative chemical analysis (EDS) of the dendritic regions and micro regions confirms changes in chemical contents before and after oxidation and after corrosion in exhaust gases. The oxidation at temperature 750°C for 200 hours in air and for two month in exhaust gases did not influence on the morphology of the clad layers neither on the top part nor in the clad/steel interface. However changes in chemical composition were observed. On the surface of both sort of clads the oxide layers were observed. These sorts of layers are resistant for the hot exhausted gases. Research limitations/implications: During the future research kinetic analyze of high temperature corrosion should be done also for different temperature and times of the process. Practical implications: The layers were designed as a method to prolong service time for the ship engine exhausted valve. Originality/value: The chemical composition of the powder was new one. Also using the laser cladding technique for ship engine parts is a subject of interest.

Słowa kluczowe

EN

corrosion; oxidation resistance; cobalt base alloy

PL

korozja; odporność na utlenianie; stop na osnowie kobaltu

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2006
• Tom: Vol. 18, nr 1-2
• Strony: 235--238
• Opis fizyczny: Bibliogr. 16 poz., rys., wykr.

Twórcy

autor

Smolenska H.

• Division Mechanical Department, Gdansk University of Technology, ul. Narutowicza 11/12, 80-952 Gdansk, Poland

Bibliografia

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