Title

WORK ROLLS BEHAVIOUR IN THE ROUGHING STANDS AT SOUTH AMERICAN HOT STRIP MILLS

WORK ROLLS BEHAVIOUR IN THE ROUGHING STANDS AT SOUTH AMERICAN HOT STRIP MILLS

Authorship

Tremea, Alberto; Grespi, Massimo

Tremea, Alberto

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Grespi, Massimo

I am this author

DOI

10.5151/2594-5297-00007

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Abstract

The work roll in chromium steel is the typical type of roll for the roughing stands of a hot strip mill. This application, very hard from a thermal point of view, needs rolls made in high-strength alloys that can withstand heavy rolling loads and wear at high temperature. In this regards, already exist rolls with superior mechanical properties to those of rolls made in chromium steel. An example is represented by semi-hss rolls called in this way in analogy to the classification of tool steels. Laboratory tests on the semi-hss material has shown optimal results in terms of wear and thermal shock resistance, but in service it requires careful management if you want to exploit these features. For this reason, the operations in the roll shop hold a great importance both in routine grinding phases and when a roll is subjected to an accident. This work aims to underline that the synergy between the roll shop and the roll producer is the only way to optimize the roll performance. Working with this approach becomes possible a reasonable cost reduction for the roll shop as well a correct evaluation of real yield of the roll. The paper outlines the operating situations of roughing stands in some South American mills. This comparison can certainly help to better understand how to manage the many rolling variables when we want to evaluate the behaviour of a roughing work roll.

The work roll in chromium steel is the typical type of roll for the roughing stands of a hot strip mill. This application, very hard from a thermal point of view, needs rolls made in high-strength alloys that can withstand heavy rolling loads and wear at high temperature. In this regards, already exist rolls with superior mechanical properties to those of rolls made in chromium steel. An example is represented by semi-hss rolls called in this way in analogy to the classification of tool steels. Laboratory tests on the semi-hss material has shown optimal results in terms of wear and thermal shock resistance, but in service it requires careful management if you want to exploit these features. For this reason, the operations in the roll shop hold a great importance both in routine grinding phases and when a roll is subjected to an accident. This work aims to underline that the synergy between the roll shop and the roll producer is the only way to optimize the roll performance. Working with this approach becomes possible a reasonable cost reduction for the roll shop as well a correct evaluation of real yield of the roll. The paper outlines the operating situations of roughing stands in some South American mills. This comparison can certainly help to better understand how to manage the many rolling variables when we want to evaluate the behaviour of a roughing work roll.

Keywords

Hot rolling (roughing stands); High alloyed steel; Rollp.

Hot rolling (roughing stands); High alloyed steel; Rollp.