Abstract
	The structure of hot rolled strip from grain oriented silicon steel with Cu content of 0,44 % is analysed in this paper. The results are confronted with conventional grain oriented with Cu content of 0,03 %. No significant influence of the higher Cu content on refining the ferrite grain was proved by light microscopy. TEM and EDX analyses proved that in samples with higher Mn and Cu contents globular particles on the basis of Mn and Cu sulphides were present, in samples with lower Mn and Cu contents mainly globular particles on the basis of Cu sulphide were present and they were evenly distributed in the size of up to 80 nm. TiN and AlN particles have different morphology and size, in the chemical conception with high Cu content cubical morphology and the size of 100 to 400 nm; in conventional grain oriented silicon steel globular morphology and the size of up to 450 nm. The presence of structural free cementite was observed in all the samples. The evaluations of light and electron microscopy are completed with the characteristics of Rp0,2 and Rm and with the characteristics of A80. The higher content of Cu does not influence Elongation degressively, some problems could be caused by the segregational processes of Cu because of its lower solubility in ferrite.