Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Mechanical Properties and Microstructure of PM Mn-Cr-Mo Steels With Low Carbon Concentration

Lichańska E., Sułkowski A., Ciaś A.

Archives of Metallurgy and Materials

2016

Vol. 61, iss. 1

109--114

The effect of chemical composition of the sintering atmosphere on the microstructure and mechanical properties of PM structural low-carbon steels is presented. The base powders were Astaloy CrL, Astaloy CrM, low carbon ferromanganese and graphite C-UF. From the base powders two mixtures with compositions of Fe-3%Mn-(1.5/3%)Cr-(0.2/0.5)%Mo-0.2%C were prepared. Following pressing in a steel rigid die, compacts were sintered at 1250°C for 60 min in a semi-closed container. 5%H2-95%N2 mixture and air were the sintering atmospheres. For sintering in air, lumps of ferromanganese were placed with the compacts in the container. After sintering, half of the samples were tempered at 200°C for 60 minutes in air. Mechanical tests (tensile, bend, toughness, hardness) and microstructural investigations were performed. The microstructures of the steels were inhomogeneous, mainly ferritic-bainic. Tempering of steel based on Astaloy CrM sintered in an atmosphere of 5% H2-95% N2 slightly reduced tensile strength and toughness: from 748 to 734 MPa and from 7.15 to 6.83 J/cm2, respectively. Chemical composition had a greater effect; steels based on Astaloy CrL and Astaloy CrM had tensile strengths 526-665 and 672-748 MPa, hardness 280-325 and 388-421 HV, respectively. The best properties were obtained after sintering in air of Fe-3%Mn-3%Cr-0.5%Mo-0.2%C without heat treatment: tensile strength 672 MPa, toughness 6.93 J/cm2, hardness 421.1 HV, 0.2 % offset yield strength 395 MPa.

Geometrical approximations of a solid particle shape

Sułkowski A.

Chemical and Process Engineering

2007

Vol. 28, z. 3

423-434

The paper deals with the problem of solid particle shape description. A particle is considered as a compact and connected subset of a three-dimensional real space. It is assumed to be represented by its two-dimensional projective image. Two geometrical constructions approximating the particle image have been introduced. Appropriate shape factors have been defined.

Artykuł poświęcono problematyce opisu kształtu cząstki ciała stałego. Cząstka jest traktowana jako pewien zwarty i spójny podzbiór trójwymiarowej przestrzeni rzeczywistej. Zakłada się, że cząstka jest w pełni reprezentowana przez swój obraz projekcyjny. Zaproponowane zostały dwie konstrukcje geometryczne aproksymujące obraz cząstki. Zdefiniowano odpowiednie współczynniki kształtu i opisano podstawowe ich właściwości.