RSE «Karaganda State Industrial University», Temirtau, Karaganda region, Republic of Kazakhstan:

A. B. Naizabekov, Dr.Sc., Prof., Kgiu@mail.ru

O. N. Krivtcova, Ph.D.

V. A. Talmazan, Ph.D., Assistant Professor

A. S. Arbuz, Magister

JS «ArcelorMittal Temirtau», Temirtau, Karaganda region, Republic of Kazakhstan:

L. N. Aleshina, Manager

The paper is devoted to analysis of breakdown of work rolls at the cold rolling mill in the sheet rolling shop No. 3 (LPTs-3) of "ArcelorMittal Temirtau" jsc. Influence of chemical composition on roll resistance is examined. Technological (e.g. welding) and fatigue (e.g. delaminating) defects on work rolls are illustrated; the first were the cause of 36 % of defects and the second - of 47 % of defects. Taking into account features and conditions of operation of work rolls at cold rolling mills, the optimal experimental procedure - multi-factor passive experiment - has been chosen. The technique of experimental procedure, providing construction of multivariate linear regression, is concluded. All data included in the equation, such as factors (content of chemical elements) and optimization parameter (complex operating quality parameter) are processed statistically. Separate characteristics of distribution of single parameters and chemical composition of 60Kh2SMF work roll resistance are examined. The matrix of coefficients of pair correlation of complex operating quality parameter of work rolls and chemical elements of the same work rolls is presented. The equation of multivariate linear regression has been built with corresponding tests on meaning according to Student criterion and on adequacy according to Fisher criterion.

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