Section Rolling Research Articles

Heat transfer correlations for use in naturally cooled enclosures with high-power integrated circuits: Ronald D. Flack and Bruce L. Turner. IEEE Trans. Components, Hybrids Mfng Technol.CHMT-3 (3), 449 (September 1980)

Previous research associated with interference-fitted assemblies has shown that as recurring slip occurs (i.e. load to total slip, unloading and reload to total slip) there is an observed increase in the holding torque after each loading cycle. The aim of this work was to identify the reasons for this ‘torque strengthening’ phenomenon. The work also has industrial relevance in the optimum design of interference-fitted rolls used for the hot rolling of steel sections. Previous work has shown that the major contributors to the overall holding torque were the interface pressure, material properties and the coefficient of friction between component materials. In this work, neutron diffraction tests and crack compliance tests showed no correlation between the interface pressure and increased holding torque. Meanwhile, experimental holding torque tests on sample interference-fits showed that for each recurring holding torque failure (slip) in a test cycle, the holding torque increased. Subsequent wear investigations showed that the wear of the surfaces increased throughout the testing and once a specific type of wear had occurred through a ‘ploughing’ mechanism, significant damage could be done to the more expensive shaft component. These observations suggest that an effective increase in the coefficient of friction between shaft and hub is responsible for the increase in holding torque, while the same level of interface pressure is maintained throughout slipping. The research provides a basis for the optimisation of interference-fit design in order that the working lives of expensive shafts, which are prone to damage through ploughing, and brittle hubs, which are prone to sudden fracture, are maximised when experiencing recurrent slipping.

Progress in section-rolling technology in Japan

The technology of the rolling of sections has made great progress in Japan in the last 7 decades, and in the 15-year period since the introduction of universal mills development of the technology has been quite striking. Starting with the changes in mill layout, this progress is briefly discussed, and the technology that has brought about the development is described at length. Reference is made to the extension of universal rolling to the rolling of general sections, to the realization of computer control of the rolling of wide-flange beams and of full continuous rolling, to the automation of finishing operations, and, further, to energy-saving measures, which are the subject of major current interest. Lastly, the outlook for section rolling in the years ahead is considered on the basis of manufacturing facilities, manufacturing processes and demand trends, thus clearly indicating the direction in which the technology of section rolling is likely to proceed.

Rolling of bar, rod, and section: aluminium and aluminium alloy

The development of the rolling of aluminium rod has been closely allied to the introduction of aluminium for electrical conductors, first for overhead use and later for insulated cables. This led to relatively late installation of modern mills of conventional types and also to the development of continuous casting and rolling techniques particularly suited to aluminium. Although rod rolling is dominated by pure aluminium, a wide range of alloys is also rolled, which calls in some cases for special production techniques for the wirebars. Conventional rolling techniques are basically similar to those usedfor other metals but some characteristics of aluminium demand special techniques. Bar and section rolling is virtually non-existent in Europe, contrary to practice in North America, where the existence of large blooming mills for this purpose has greatly influenced rod-rolling practice.

Rolling of sections for drag links of coal conveyers

Rolling of sections for drag links of coal conveyers

Improvement of the rolling of special sections on the 550 mill

Improvement of the rolling of special sections on the 550 mill

形鋼圧延における孔型形状係数について

形鋼圧延における孔型形状係数について

Application of Mill Stands with Multiroll Sets for Precision Rolling of Simple, Shaped, and Die-rolled Sections

Application of Mill Stands with Multiroll Sets for Precision Rolling of Simple, Shaped, and Die-rolled Sections

Rolling of sections for truck tire rims on the 550 mill

Rolling of sections for truck tire rims on the 550 mill

Rolling of merchant sections in the minus range of tolerances with delivery on the basis of the theoretical weight

Rolling of merchant sections in the minus range of tolerances with delivery on the basis of the theoretical weight

Unit standardization of billets for rail and structural and heavy section rolling departments

Unit standardization of billets for rail and structural and heavy section rolling departments

Rolling of special sections

Rolling of special sections

Experimental rolling of sections from continuously cast slabs

Experimental rolling of sections from continuously cast slabs

The rolling of sections on a planetary mill

The rolling of sections on a planetary mill

The rolling of round sections on a continuous mill

The rolling of round sections on a continuous mill

The rolling of channel sections with increased taper in the finishing groove

The rolling of channel sections with increased taper in the finishing groove

Formula for ‘Spread’ in Hot Flat Rolling

An experimental investigation has been made to compare the elongation and the lateral spreading which occur during hot rolling of rectangular sections (i.e. slab or bar) between plain rolls. The results did not agree with predictions made from existing formulae for ‘spread’, and a new formula is presented which was derived empirically from the results and is of a form logically to be expected from a consideration of the factors likely to affect spread. This formula takes into account the ratio of the width of the stock to the length of the arc of contact during rolling, the ratio of the roll radius to thickness of the stock, the width to thickness ratio of the stock and the draft (or reduction). A modified formula has also been devised to take into account not only the geometrical variables but also changes in rolling temperature, steel composition, roll and bar surface condition, and speed of rolling (strain rate).

The improvement in durability of the rolls for the rolling of periodic sections

The improvement in durability of the rolls for the rolling of periodic sections

Advanced experience in medium section rolling mill operation

Advanced experience in medium section rolling mill operation