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Effect of Rhenium Addition on Microstructures and Mechanical Properties of Oxide Dispersion Strengthened Ferrtic Steels

Noh Sanghoon, Kang Suk Hoon, Kim Tae Kyu

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 4

1261--1264

EN

In this study, to investigate effects of rhenium addition on the microstructures and mechanical properties, 15Cr-1Mo ODS ferritic steels with rhenium additions were fabricated by the mechanical alloying, hot isostatic pressing, and hot rolling processes. Unremarkable differences on grain morphologies and nano-oxide distributions were estimated in the microstructure observations. However, the ODS ferritic steels with 0.5 wt.% rhenium showed higher tensile and creep strengths at elevated temperature than that without rhenium. It was found that rhenium is very effective to improve the mechanical properties.

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Microstructures and Mechanical Properties of ODS Ferritic Stainless Steels for High Temperature Service Applications

Noh Sanghoon, Kang Suk Hoon, Kim Tae Kyu

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 3

921--924

EN

In this study, ODS ferritic stainless steels were fabricated using a commercial alloy powder, and their microstructures and mechanical properties were studied to develop the advanced structural materials for high temperature service applications. Mechanical alloying and uniaxial hot pressing processes were employed to produce the ODS ferritic stainless steels. It was revealed that oxide particles in the ODS stainless steels were composed of Y-Si-O, Y-Ti-Si-O, and Y-Hf-Si-O complex oxides were observed depending on minor alloying elements, Ti and Hf. The ODS ferritic stainless steel with a Hf addition presented ultra-fine grains with uniform distributions of fine complex oxide particles which located in grains and on the grain boundaries. These favorable microstructures led to superior tensile properties than commercial stainless steel and ODS ferritic steel with Ti addition at elevated temperature.

3

Effect of Plasma Modification on the Chemical Structure of a Polyethylene Terephthalate Fabrics Surface

Sójka-Ledakowicz J, Kudzin M

Fibres & Textiles in Eastern Europe

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2014

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Vol. 22, no. 6 (108)

118--122

EN

Investigations focused on physico-chemical modifications of a polyethylene terephthalate (PET) nonwoven fabric fibre surface. To improve the adhesive properties of textile products towards TiO2, their surface was treated in low-temperature plasma (cold plasma). Plasma treatment of PET fabrics was performed in carbon dioxide and/or argon pressure. Potential changes in the chemical structure of polyester fabric can be caused by the following: a homolytic splitting of the ester bonds, a release of volatile degradation products (mainly CO and CO2), a cross-linking, reactions of macro radicals [alkyl (CH2-CH2~) and phenyl (C6H4~)] with oxygen, and a subsequent formation of hydroxy-aromatic rings. Experimental investigations confirmed the fact of modification of the chemical structure of the PET surface caused by plasma treatment of the fibre surface.

PL

Badania dotyczyły fizykochemicznej modyfikacji powierzchni włóknin z poli(tereftalanu etylenu) (PET). W celu polepszenia właściwości adhezyjnych włóknin względem TiO2 ich powierzchnia była modyfikowana działaniem plazmy niskotemperaturowej (cold plasma). Obróbkę plazmą włóknin przeprowadzono w atmosferze dwutlenku węgla lub argonu. Autorzy zakładają, że obserwowane zmiany w strukturze chemicznej badanych włóknin mogą być spowodowane oddziaływaniem plazmy na powierzchnię włókniny, indukującym przebieg procesów: hemolitycznego rozszczepienia wiązań estrowych, uwolnienia lotnych produktów rozkładu (głównie CO i CO2), sieciowania przebiegu reakcji makro-rodników [alkilowych ( CH2- CH2 ~) i fenylowych ( C6H4 ~)] z tlenem i powstawaniem hydroksy-aromatycznych pierścieni. Zmiany w strukturze chemicznej powierzchni włóknin zostały potwierdzone eksperymentalnie.