Issue 37

I. Mazur et alii, Frattura ed Integrità Strutturale, 37 (2016) 287-296; DOI: 10.3221/IGF-ESIS.37.38 293 The functioning of modules is based on the notion of a «criticality» of defect. The criticality is defined for the cold-rolling mill by the probability of emergency shutdown of the mill due to the breach of flat bar caused by the surface defect. An algorithm of conferment of code of criticality (from 0 up to 7) against of the steel grade, of the type of defect, its location (edge, center of pre-rolling) and of linear sizes is worked out on the basis of experimental data on the breakness of flat bars obtained on the mills 2030 and 1400. A decision is made on the further processing of roll (the change of status «critical/ uncritical», cutting out of defect, decrease of speed of rolling on the problem sectors and the others) or its destination is altered at the processing of rolls on the units of preparation (in front of the mill of cold rolling) according to the information about the defects presenting on the flat bar and their codes of criticality. The functioning of modules is based on the notion of a «criticality» of defect. The criticality is defined for the cold-rolling mill by the probability of emergency shutdown of the mill due to the breach of flat bar caused by the surface defect. An algorithm of conferment of code of criticality (from 0 up to 7) against of the steel grade, of the type of defect, its location (edge, center of pre-rolling) and of linear sizes is worked out on the basis of experimental data on the breakness of flat bars obtained on the mills 2030 and 1400. A decision is made on the further processing of roll (the change of status «critical/ uncritical», cutting out of defect, decrease of speed of rolling on the problem sectors and the others) or its destination is altered at the processing of rolls on the units of preparation (in front of the mill of cold rolling) according to the information about the defects presenting on the flat bar and their codes of criticality. A module of visualization of defects of surface of hot-rolled flat bars with the reference to the identifier of roll is intended for the analysis of rise of defects depending on the fusion, lot, metal grade, mode of its rolling and so on (Fig. 6). The algorithm materialized in the module makes it possible to carry out the analysis of formation of surface defects on-line mode for the flat bars rolled on the mill 2000, and in the mode off-line on the archive data of rolled flat bars. It makes possible to reveal in time the regularity of distribution of defects, to find the causes of rise, to propose the actions for their elimination and to decrease the losses from rejects and insufficient production thereby. These are some results of introduction of ASIS: the use of system of control of surface condition with additional applications led to the decrease of stoppages of the mill 2030 for 14,4 % in 2004, for 31,2 % in 2005 as compared with 2003; in April – August 2009 the control with the use of ASIS of hot-rolled steel of the grade St24 supplied to the europium client made it possible to the experts of quality to take from the shipping and move it into the insufficient production of 112 rolls at the certification of the production that amounted 3,0% from shipped. The considered user’s applications are installed on the working stations of production engineers of different services included into information net of the industrial complex. The engineering center, oxygen-converter plants, sheet-rolling production sectors, subdivisions of market department and other subdivisions are among them. C ONCLUSIONS he diagnosis of surface defects в rolling production is a complicated and multiple-factor process. The experience of introduction of the system of control of quality of surface on the uninterrupted wide strip mill of hot-rolling and also its further use showed that automatic detection and classification of surface defects in the end-to-end technology of production of sheet products make it possible: to secure a provision of the requirements of consumers on the quality of the surface of the rolled metal with the submission of electronic passport; to provide 100 % control of surface of all flat bars rolled on the mill for the detection of defects of pouring and hot rolling; to provide automated systems of subsequent process stages by the information about the defects of surface of hot-rolled metal; to carry out monitoring of quality of surface in the adjacent process stages; to carry out an audit of the existing technologies of rolled metal production and develop the actions on their improvement. The management of technology of process stages adjacent with hot rolling with the use of results obtained by the system of control of quality of surface opens good prospects on the decrease of insufficient production and to the increase of productive efficiency. T