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Influence of severe plastic deformation by the ECAP method on structure and properties of the P2-04BCh steel

Greger M., Vodarek V., Kander L., Cizek L.

Archives of Materials Science and Engineering

2009

Vol. 37, nr 1

13-20

Purpose: Maim aim of this paper is to describe the plastic deformation executed by ECAE of low carbon steel. The ECAE method lead to significant improvement of strength of investigated material. Design/methodology/approach: Experiments were planned and realised an the temperature ranging from room temperature up 280oC. After application of deformation the structure was investigated in dependence on accumulation of deformation and deformation temperature as well as abovementioned final properties. Findings: Accumulated deformation varied from the value 2 to 8. Investigation of structure by electron microscopy was made with use microscope JEOL JEM 2100. Mechanical properties were investigated by tensile test. Statistic evaluation of angular disorientation and of size of grains/sub-grains was also made with use of electron diffraction (EBSD) in combination with scanning electron microscope FEG SEM Philips. Practical implications: The technology ECAE was applied on low carbon steel. It was verification of ECAE application possibility on steel P2-04BCH importantly for following applying on similar kinds of steel, because ECAE deformation influence. Originality/value: The results from his work shall be useful in determining conditions for fabrication of nanocrystalline or sub-microcrystalline steel by the ECAE technology.

Properties of a Nb-V-Ti microalloyed steel influenced by cold rolling and annealing

Janosec M., Schindler I., Palat J., Cizek L., Vodarek V., Mistecky E., Ruzicka M., Dobrzański L. A., Rusz S., Suchanek P.

Journal of Achievements in Materials and Manufacturing Engineering

2007

Vol. 20, nr 1-2

251-254

Purpose: was to investigate impact of cold forming and annealing on microstructural and mechanical properties of HSLA steel. Design/methodology/approach: Testing of Nb-V-Ti microalloyed strip steel was based on a combination of cold rolling, recrystallization annealing, mechanical testing, metallography and TEM. Findings: It was confirmed that by a suitable combination of size of previous cold reduction size and parameters of the following annealing it is possible to influence considerably a complex of mechanical properties of particular strips. Strength as well as plastic properties depended on the course of recrystallization and precipitates' coarsening during annealing. Research limitations/implications: The experiment should be supplemented by the more detailed analyses of microstructure. Practical implications: The results may be utilized for optimization of terms of heat treatment in a cold rolling mill, especially in accordance with specific requirements for a relation between plastic and strength properties of the investigated steel. Originality/value: Research possibilities of VSB-TUO in the sphere of cold rolling of Nb-V-Ti HSLA steel were introduced in combination with the complex approach to processing of the obtained results.

Heat treatment of supermartensitic steels.

Vodarek V., Tvrdy M., Korcak A.

Inżynieria Materiałowa

2001

R. XXII, nr 5

939-941

Low carbon supermartensitic 13%Cr steels with 4-6%Ni and 0-2.5%Mo additions have been developed from type AISI 420 steels for applications in the oil industry. They offer significantly better weldability, improved general corrosion resistance, particularly in carbon dioxide environments, and some grades exhibit improved resistance to sulphide stress corrosion cracking. In this paper results of detailed investigations on a 13Cr-6Ni-2.5Mo-Ti steel after quenching and double tempering are presented. Microstructural studies were carried out using optical microscopy, transmission electron microscopy and X-ray diffractometry. The results prove that formation of austenite during tempering at both 690 and 620 degrees centigrade is accompanied by intensive precipitation of Fe-Mo Laves phase particles.