Influence of sherardizing on working properties of metal parts subjected to prior heat treatment

The article reveals the data concerning the mechanical properties changes of heat-treated steel articles subjected to thermo diffusion pack cementation. The temperature frames of thermo diffusion influence on tensile strength were determined for heat-treaded steel articles. Results of tensile test of high strength bolts treated using thermo diffusion pack cementation at 420 °C show no any effect from the side of pack cementation treatment on working properties of the tested samples. It is shown that in conditions of cyclic fatigue loading thermo diffusion pack cementation of heat treated article may leads to strength loss that can be explained by formation of solid intermetallic phases in a surface area of the article.

Identification of soybean Kunitz-free progenies in full-sib crossing

Kunitz trypsin inhibitor (KTI) is part of the anti-nutritional complex present in soybeans. Soybean grain without KTI can be used in the diet of non-ruminants without prior heat treatment. In order to obtain soybean lines with reduced content of anti-nutrients in the grain, in the first place without KTI, we crossed the adapted genotype of standard grain quality (variety Kador) with the genotype without KTI, less adapted to our growing conditions (variety Kunitz). A segregating generation was obtained from which the three most productive F3 lines, heterozygous for the presence of KTI, were selected for the new crossing cycle. Two combinations of full-sib (FS) crosses with different numbers of successfully crossed plants were realized. Determination of the presence of KTI in progeny developed from selected lines originating from Kunitz x Kador crosses and their combinations of FS crosses was performed using protein markers on a native polyacrylamide gel. Based on the electrophoregram, it was noticed that the bands corresponding to the KTI position are not of the same intensity. The analysis was done from a group sample, so it is possible that the sample contains grains with and without KTI. Ten progenies of maternal lines and five progenies of FS crosses without a band corresponding to the KTI position were identified on the electrophoregram. A total of four progenies with grain yield per plant at the level and better than the more productive parent can be considered promising for the further selection process.