"METALTEHNOMASH" Metallurgical technology for mechanical engineering

Improving the technology of cold rolling of electrical steel, providing greater stability of the process.

Period: 2003-2004
Customer: OJSC "NLMK"

The aim of the work is to improve the technological modes of electrical steel rolling in 4-stands 1400 mill of SRS-5, providing greater stability of the rolling process and reduce strip breakage.

Additional information

THE MAIN SECTIONS OF WORK:

1. STABILITY ANALYSIS OF ROLLING ON 4-STANDS MILL 1400 AND WAYS TO IMPROVE IT

2. COMPARATIVE ANALYSIS OF ROLLING USING DIFFERENT LUBRICATION AND COOLING LIQUIDS

3. DETERMINATION OF MINIMUM STRIP THICKNESS FOR 4-STANDS MILL 1400

4. RATIONALE AND DEVELOPMENT OF THE NEW ROLLING MODE, EXPERIMENTAL CHECKING OF ITS REPRODUCIBILITY
4.1 Rationale for the new mode of rolling
4.2 Checking the reproducibility of the proposed rolling mode

5. RESULTS OF INDUSTRIAL TESTING OF A NEW DEVELOPED ROLLING MODE
5.1 Analysis of changes in strip breakage
5.2 Analysis of changes in rolling load conditions
5.3 Analysis of changes in the inter-stand tension variation
5.4 Analysis of changes in longitudinal thickness variation
5.5 Analysis of thermal working conditions of the mill and the strip surface quality
5.6 Analysis of rolls damaging
5.7 Recommendations

6. OPTIMIZATION OF DEFORMATION-POWER AND KINEMATIC PARAMETERS OF THE ROLLING PROCESS, AS WELL AS COOLANT CONSUMPTION IN MILL STANDS UNDER DIFFERENT ROLLING CONDITIONS

7. ANALYSIS OF THE CAUSES OF SIMULTANEOUS APPEARING OF EDGE WAVINESS AND BUCKLING OF CENTRAL PART, AS WELL IDENTIFYING WAYS OF THIS UNWANTED EFFECT ELIMINATING

8. PROVIDING A REQUIRED SURFACE MICRO GEOMETRY OF FINISHED CARBON STEEL STRIPS

9. WAYS OF STRIP FLATNESS INCREASING OF ELECTRICAL STEEL ON REVERSING 1200 MILL IN SRS-2

10. ANALYSIS OF THE ACHIEVED INDICATORS OF STABILITY IN ROLLING PROCESS, STRIPS BREAKAGE AND PRODUCTIVITY THROUGH THE APPLICATION OF PROPOSED ROLLING MODE ON THE 4-STANDS 1400 MILL SRS-5

11. RECOMMENDATIONS AND DRAFT AMENDMENTS TO TI

The working window of a computer system WinColdRolling
(Editor of plastometer data)

results of experimental plastometer data processing of rheological properties of high-silicon electrical steel (the method of multidimensional inter- and extrapolation)

Estimated comparison of baseline and experimental modes of rolling

base conditions

experimental mode

The main results
1. The analysis is fulfilled of the rolling process stability on a 4-stands 1400 mill NLMK and breakage of rolled strips. Opportunities are identified to reduce breakage during strip rolling of the most problematic in this sense metal - with thickness of 0.48 mm of high-silicon ([Si] = 4%) steel.
2. Analysis of the results of industrial-scale experiment showed that the proposed mode of strips rolling reduced strip breakages compared to the baseline from 30.8% to 22%, an 8.8% absolute and 28.5% relative.