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Optimization of forming temperature of 100CrMnSi6-4 bearing steel under partial heating

Doležal P., Zapletal J., Klakurková L., Švejcar J.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2008

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z. 92

65-65

EN

The paper focuses on problems of optimizing the forming temperature of grade 100CrMnSi6-4 bearing steel under partial heating. In order to assess its formability, tensile tests at elevated temperatures ranging from 100 to 800 °C were carried out. Tensile diagrams revealed jump changes of mechanical properties in the brittle region under blue heat and in the region of phase transformations. Experimental examination was then concentrated on assessing the plastic deformation capability of the material under pressure at elevated temperatures, by means of the upsetting test. Another goal of the paper consisted in comparing the two experimental methods chosen for establishing the optimum temperatures of forming grade 100CrMnSi6-4 bearing steels at elevated temperatures. To have a complex assessment of the experimental material the structure and phase analyses of the bearing steel were performed in dependence on heating temperature.

2

Establishing optimum forming temperature of 100CrMo7-3 bearing steel under partial heating

Klakurková L., Doležal P., Zapletal J., Švejcar J.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2008

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z. 92

73-73

EN

The forming process is associated with the plastic deformation capability of materials. The formability of metals and alloys is influenced by physical-metallurgical properties of material and by external forming conditions, forming temperature in particular. A kind of borderline for the division of forming is the recrystallization temperature, according to which forming is divided into cold forming, partially hot forming and hot forming. The paper is concerned with problems of optimizing the temperature of forming grade 100CrMo7-3 bearing steel under partial heating. Experimental establishment of the optimum range of forming temperatures was based on the results of tensile testing at elevated temperatures from 100 to 800 °C. Experimental verification of the behaviour of bearing steel under pressure was conducted via the upsetting test at elevated temperatures. The experimental part of the work is also concerned with the analysis of phase composition of grade 100CrMo7-3 bearing steel using computer simulation, and by the verification of simulation via metallographic evaluation.

3

Vliv technologie výroby odlitku ze slitiny AZ 91 na jeho kvalitu a strukturu

Ptácková M., Klakurková L., Juřička I.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2007

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Vol. 321, z. 89

41-41

EN

The paper summarizes the results of structure analyses focused on differences in the technologies of manufacturing AZ91-alloy castings. The following technologies were used: A) die casting B) gravity casting into ceramic moulds As to their shape complexity the two castings are similar and are of roughly the same wall thickness. The die casting was selected form the manufacturing process while the precision casting made in a ceramic mould (shell mould) was cast individually within the process of verifying the potentials of manufacturing precise castings by the technology of investment casting into ceramic moulds.

4

The optimization of laser cutting parameters with respect to quality and heat affected cutting area

Klakurková L., Doležal P., Kubícek J.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2007

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Vol. 321, z. 89

27-27

EN

The utilization of laser is wide and namely in the field of heat cutting of materials where this method is the most progressive. The optimization of all parameters of cutting arrangement is the most important for achievement the best quality of cutting area; it means rate, power, pressure, and focal distance of laser. Suitable setting of various parameters can influence the quality of cutting area. The quality of specific cutting material is also considerable factor of cutting process. The finding optimal cutting conditions for achievement maximal cutting rate were the goal of this work. The setting of individual parameters was evaluated with regard to quality and heat affected cutting area. The carbon steel grade 11 373 and high-alloy Cr-Ni steel 17 240.2 were used for experiments. The quality and heat affected cutting area of individual materials were evaluated by means of measurements of roughness and metallographic evaluation and microhardness of heat affected zone.

5

Metalografický rozbor pájených spojů pinů

Janová D., Ptáčkova M., Klakurková L.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2007

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Vol. 321, z. 89

23-23

6

ADI - a prospective structural material

Dorazil E., Věchet S., Kohout J., Klakurková L.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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1999

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z. 59

103-106

EN

Austempered ductile iron (ADI) presents relatively new high strength structural material with very good mechanical and technological properties along with relatively low price (see Fig. 1). This type of nodular cast iron is produced in wide measure not only in large and developed countries (U.S.A. - full half of world-wide production, Japan, China, Germany, Great Britain, France, Italy, Sweden etc.) but also in countries comparable with our country (Finland, Netherlands, Belgium etc.). Word-wide production per year exceeded 60,000 tons in 1995 [1], in 2005 already the production of 230,000 tons is expected (Fig. 2).