Strip mill

Abstract: A scheme for the speed control of rolling mill drives is presented. The proposed speed controller is based on a two degree of freedom (TDF) structure and uses an observer-based state feedback compensator for the major control loop. The control method yields a robust system with respect to system uncertainties and modeling errors and is very effective for vibration suppression. Experimental verification is carried out on a prototype rolling mill mini-model system. The experimental drive system has a three-mass-model structure (motor-gear-load) connected by low stiffness shafts. The mechanical resonances and the inertia ratios between the motor, gear, and load are comparable to those of an actual rolling mill system (resonant frequencies are at 17.4 Hz and 51.32 Hz). The proposed scheme is compared to the conventional proportional plus integral controller, and the performance of each scheme is presented. A high closed loop speed bandwidth was obtained with the proposed TDF speed controller. >

Abstract: A paired comparison is made between rival attempts to develop the first continuous rolling mill for wide strip in the USA during the 1920?s. One firm was secretive, the other relied upon collaboration. Development of the wide strip mill is a natural experiment comparing closed and open innovation since two firms were competing for the same target using different institutional arrangements for their R&D. Wide strip rolling technology was developed by rival teams in the USA during the mid-1920?s. The less successful team at Armco, Ashland, Kentucky was closed to outside influences. Breakthroughs came from Columbia Steel at Butler, Pennsylvania which pursued an open pattern of cooperation with equipment suppliers. Columbia Steel?s collaboration with machinery suppliers, use of independent advice on bearing technology and willingness to learn from precursors in copper rolling enabled them to build a successful wide strip mill complex, commissioned in 1926. Butler established the dominant design for the next 80 years. The leading equipment supplier at Butler, the United Engineering and Foundry Co., led global sales of the technology for four decades. It is not clear how far this example of successful open innovation in the US inter-war economy is typical. Historical studies of the management of R&D focus on formal, science based research in large corporate labs rather than engineering development.

Abstract: An analytical model for strip rolling operating in the mixed regime is developed. The model combines analysis for the influence of bulk plastic deformation on the effective hardness of the strip asperities with an approach to allow for the influence of roughness on lubricant flow. An approximate correction for thermal effects is also included. The predictions of the model are compared with experimental measurements of film thickness and slip. Presented as a Society of Tribologists and Lubrication Engineers paper at the STLE/ASME Tribology Conference in New Orleans, Louisiana, October 24–27, 1993