Abstract
	Results of the high temperature properties investigation of low carbon steels KOHAL 200, KODUR E 380 TS and KOSIL 235 LL in cast state determined by static tensile tests with and without melting the process zone are presented in the contribution. The deformation rate was 0,471.10-3 s-1. Main attention was paid to the temperature region from solidus to 900°C. The temperature dependence of ultimate strength values in the interval from solidus to about 945°C was practically identical for all investigated steels. It weren't established any differences in the strength temperature dependence between the specimens with melted and those with non-melted process zone. There exists a temperature interval of high plasticity at high temperatures, in which the reduction of area reaches nearly 100 %. The steels undergo a second plastic minimum at lower temperatures, where their reduction of area falls down to about 20 - 50 %. Intergranular fracture occurs on the fracture surfaces of specimens broken in this region. 	The temperature dependence of the reduction of area had an individual character for each investigated steel type. The narrowest area of the high plasticity, 100 - 150 C was found for the steel KOHAL 200. An expressive increase of the ultimate strength, more than 100 %, was determined for notched specimens. The influence of notch on the reduction of area values was exercised by reduction of area drop up to about 30 - 50 %, primarily in the vicinity of the transition to the second plastic minimum.