GB2035169A

GB2035169A - Roll forming of metal

Info

Publication number: GB2035169A
Application number: GB7946326A
Authority: GB
Original assignee: British Steel Corp
Current assignee: British Steel Corp
Priority date: 1978-11-28
Filing date: 1978-11-28
Publication date: 1980-06-18
Also published as: GB2035169B

Abstract

A method of roll forming metal strip, sheet, or plate to a desired profile with a series of roll stages in which the leading end of the material to be rolled is preformed to a profile prior to shaping within the first rolling stage of the series. Preforming of the leading end of the material may be effected by means of press tooling situated either in- line with the rolling stages or off- line. Continuous or reversing roll forming follows the initial preforming step. <IMAGE>

Description

SPECIFICATION Roll forming of metal This invention relates to methods of roll forming metal feed stock in strip sheet or plate form.

Roll forming is a process conventionally carried out at ambient temperature in which flat metal strip sheet or plate (hereinafter referred to simply as strip) is progressively formed into a desired shape by being passed through a series of rolling stages arranged in tandem. Each rolling stage comprises a pair of vertically or horizontally spaced rolls mounted on, respectively, horizontal or vertical spindles and plays its particular part in building up the profile required. The number of roll stages depends upon the intricacies of the profile to be imparted to the strip and upon the gauge of the material used. Hithertoo roll forming machines have typically comprised between 6-1 2 rolling stages.

According to the present invention there is provided a method of roll forming metallic material in strips, sheet or plate form to a desired profile within a series of roll stages wherein the leading end of the material is preformed to an intermediate profile prior to shaping within the first rolling stage of the series and/or one or more intermediate stages of the series.

Each roll stage may comprise one of several roll passes cut in the roll barrels of a single mill. Alternatively each rolling stage may comprise one pair of rolls of a tandem series of such roll pairs.

The roll forming may be carried out at ambient temperature or within a controlled temperature range above ambient temperature. Roll forming may, for example, be effected within a temperature range of between 500-700'C.

Preforming of the leading end of the material may be effected by means of press tooling situated either in-line with the rolling stages or off-line.

The strip, sheet or plate material may be subjected to discrete heating at locations corresponding to subsequent changes in profile to assist shaping of the material within the succeeding roll stage. Localised heating may be effected by concentrating the heat source to give line heating of the feedstock over a predetermined length.

The invention will now be described by way of example with reference to the accompanying diagrammatic drawing; in which Figure 1 is a schematic perspective view of roll forming apparatus suitable for carrying out the present invention; and Figure 2 is a perspective view of alternative roll forming apparatus suitable for carrying out the present invention.

Fig. 1 illustrates press tooling 1 operable to preform the leading end of the strip 2 to be shaped by roll forming and two rolling stages 3,4 of a roll forming line. Each rolling stage 3,4 comprises a pair of vertically spaced rolls each mounted for rotation on horizontally disposed spindles. The barrels of each roll pair are shaped to impress upon the strip a profile closely akin to the final profile to be imparted to the strip. Thus as the strip 2 is fed from one rolling stage to the next, its profile progressively changes until, following the final rolling stage, the strip assumes the final required profile.

In a conventional roll forming line the strip is fed into the first stage of the line with a flat profile. Thus a number of rolling stages are required to impose even an intermediate profile upon the strip. In the apparatus illustrated in Fig. 1, such an intermediate profile is achieved through preforming the leading end of the strip 2 within the press tooling 1. This preforming enables the strip to enter the rolling stage 3, which is equivalent to an intermediate rolling stage of a conventional roll firming line. The strip is then sequentially fed through roll stage 4 and any succeeding roll stages necessary to impart the final required profile to the strip.

In the apparatus illustrated in Fig. 2, the several roll stages are each formed within the roll barrels of a single pair of vertically spaced rolls 5. As the strip 2 leaves one of these rolling stages, it is moved laterally and then returned through the adjacent roll stage of the rolls.

In both embodiments the roll forming operation may be carried out at a temperature above ambient, e.g. between 500-700 C to confer specific microstructural refinement of the metal structure compatable with property improvement and in particular impact resistance. Furthermore, localised heating of the strip may be effected at locations upstream of one or more of the roll stages to assist in the formation of angles or sharp corners within the succeeding roll stage; heating may be effected, for example, by infra-red or gas jet heaters.

1. A method of roll forming metallic material in strip, sheet or plate form to a desired profile within a series of roll stages wherein the leading end of the material is preformed to an intermediate profile prior to shaping within the first rolling stage of the series and/or one or more intermediate stages of the series.

2. A method as claimed in claim 1 wherein each roll stage comprises one of several roll passes cut in the roll barrels of a single mill.

3. A method as claimed in claim 1 wherein each rolling stage comprises one pair of rolls of a tandem series of such roll pairs.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Roll forming of metal This invention relates to methods of roll forming metal feed stock in strip sheet or plate form. Roll forming is a process conventionally carried out at ambient temperature in which flat metal strip sheet or plate (hereinafter referred to simply as strip) is progressively formed into a desired shape by being passed through a series of rolling stages arranged in tandem. Each rolling stage comprises a pair of vertically or horizontally spaced rolls mounted on, respectively, horizontal or vertical spindles and plays its particular part in building up the profile required. The number of roll stages depends upon the intricacies of the profile to be imparted to the strip and upon the gauge of the material used. Hithertoo roll forming machines have typically comprised between 6-1 2 rolling stages. According to the present invention there is provided a method of roll forming metallic material in strips, sheet or plate form to a desired profile within a series of roll stages wherein the leading end of the material is preformed to an intermediate profile prior to shaping within the first rolling stage of the series and/or one or more intermediate stages of the series. Each roll stage may comprise one of several roll passes cut in the roll barrels of a single mill. Alternatively each rolling stage may comprise one pair of rolls of a tandem series of such roll pairs. The roll forming may be carried out at ambient temperature or within a controlled temperature range above ambient temperature. Roll forming may, for example, be effected within a temperature range of between 500-700'C. Preforming of the leading end of the material may be effected by means of press tooling situated either in-line with the rolling stages or off-line. The strip, sheet or plate material may be subjected to discrete heating at locations corresponding to subsequent changes in profile to assist shaping of the material within the succeeding roll stage. Localised heating may be effected by concentrating the heat source to give line heating of the feedstock over a predetermined length. The invention will now be described by way of example with reference to the accompanying diagrammatic drawing; in which Figure 1 is a schematic perspective view of roll forming apparatus suitable for carrying out the present invention; and Figure 2 is a perspective view of alternative roll forming apparatus suitable for carrying out the present invention. Fig. 1 illustrates press tooling 1 operable to preform the leading end of the strip 2 to be shaped by roll forming and two rolling stages 3,4 of a roll forming line. Each rolling stage 3,4 comprises a pair of vertically spaced rolls each mounted for rotation on horizontally disposed spindles. The barrels of each roll pair are shaped to impress upon the strip a profile closely akin to the final profile to be imparted to the strip. Thus as the strip 2 is fed from one rolling stage to the next, its profile progressively changes until, following the final rolling stage, the strip assumes the final required profile. In a conventional roll forming line the strip is fed into the first stage of the line with a flat profile. Thus a number of rolling stages are required to impose even an intermediate profile upon the strip. In the apparatus illustrated in Fig. 1, such an intermediate profile is achieved through preforming the leading end of the strip 2 within the press tooling 1. This preforming enables the strip to enter the rolling stage 3, which is equivalent to an intermediate rolling stage of a conventional roll firming line. The strip is then sequentially fed through roll stage 4 and any succeeding roll stages necessary to impart the final required profile to the strip. In the apparatus illustrated in Fig. 2, the several roll stages are each formed within the roll barrels of a single pair of vertically spaced rolls 5. As the strip 2 leaves one of these rolling stages, it is moved laterally and then returned through the adjacent roll stage of the rolls. In both embodiments the roll forming operation may be carried out at a temperature above ambient, e.g. between 500-700 C to confer specific microstructural refinement of the metal structure compatable with property improvement and in particular impact resistance. Furthermore, localised heating of the strip may be effected at locations upstream of one or more of the roll stages to assist in the formation of angles or sharp corners within the succeeding roll stage; heating may be effected, for example, by infra-red or gas jet heaters. CLAIMS

4. A method as claimed in anyone of the preceding claims wherein the roll forming is carried out at ambient temperature.

5. A method as claimed in anyone of claims 1 to 3 wherein the roll forming is carried out within a controlled temperature range above ambient temperature.

6. A method as claimed in claim 5 wherein the temperature range lies within a temperature range of between 500 and 700 C.

7. A method as claimed in anyone of the preceding claims wherein preforming of the leading end of the material is effected by means of press tooling situated either in-line with the rolling stages or off-line.

8. A method as claimed in anyone of the preceding claims wherein the strip, sheet or plate material is subjected to discrete heating at locations corresponding to subsequent changes in profile to assist shaping of the material within the succeeding roll stage.

9. A method as claimed in claim 8 wherein localised heating is effected by concentrating the heat source to give line heating of the feedstock over a predetermined length.

10. A method of roll forming metallic material in strip, sheet or plate form substantially as herein described and as illustrated in Fig. 1 or Fig. 2 of the accompanying drawings.