During the permanent toughening to requirements to quality of metall, especially in part of providing the homogeneity of makrostruktury of the finished productc further perfection of both existent charts of rolling and construction of calibers is needed. The all aforesaid to a full degree behaves to the problem of production of round purveyance of large diameter (more than 200 mm) on the purveyances prodicing rolling mill, which uses continuouslypoured bloom.
Results of analysis of existent charts of rolling and construction of calibers in a rolling mill 900 of 950/900 OAO DMZ and OAO OEMK were foundation for conducting of laboratory researches. They modelling the existent process of rolling in a scale 1:10 and allowing to explore influencing of regulation process on extraction on passage-ways on working of internal layers of round purveyance with a diameter in 275 mm.
As parameters optimizations are chosen:
a) infex of widening δb/δh;
á) index of the accumulated deformation δij;
â) size of cuted ends is Êîáð=lîáð/l0, where lîáð is total length of the cuted ends, mm; l0 is initial length of roll, mm.
The varied factors during an experiment were chosen:
à) relation of sides of the rolled metall h0/b0;
á) The deformations relation coefficient in the 1st and 2nd passage-ways of Êe1/ Êe2 = Å1/Å2 is a size of the relative compression in the 1st and 2nd passage-ways accordingly;
â) relation of a ride diameter of rollers toward the initial height of the rolled metall Dk/h0
Three series of standards were set, which had been modelling the blooms for production a round purveyance. After dividing of rolls into two equal halves along the apeak-transversal plane of symmetry (VPPS), on the internal surface of one of halves, a coordinate scale in 0,35...0,5 mm depth with a step in 2 mm were inflicted. The talc agglutination and pressurizing of standards were made after filling of appearing slots. An experiment was conducted on a laboratory one-rolling mill device 100 with the specially made rolls. Diring the design of contact terms on the surface of standards the talc was inflicted.
As a result of the conducted experiments became obvious, that basic influence on cuted ends size (78-90%) from total size of cuts during 2 passage-ways makes the terms of deformation in the first passage-way. In addition, goted character of dependence allows to talk about optimization of parameter from position of minimization of materialcapacity of process. It is necessary similarly to mark that on all standards after the first passage-way there was ordinary «cutting», which talks about of uneven character of deformation. So, the conducted researches showed that from three factors (Êe1/ Êe2, Dk/h0, h0/b0) the most substantial influencing is possessed by Êe1/ Êe2. Thus with the purpose of improvement of working in of internal layers of metall, it is neccecary to reach the optimized values of parameter Êe1/ Êe2.