A temper mill is a

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

sheet or steel plate processing line composed of a horizontal pass

cold rolling In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. The concept is simi ...

mill Mill may refer to: Science and technology * Factory * Mill (grinding) * Milling (machining) * Millwork * Paper mill * Steel mill, a factory for the manufacture of steel * Sugarcane mill * Textile mill * List of types of mill * Mill, the arithmetic ...

stand, entry and exit conveyor tables and upstream and downstream equipment depending on the design and nature of the processing system. The primary purpose of a temper mill is to improve the

surface finish Surface finish, also known as surface texture or surface topography, is the nature of a interface (matter), surface as defined by the three characteristics of lay, surface roughness, and waviness.. It comprises the small, local deviations of a ...

on steel products.

Components

A typical type of temper mill installation includes entry equipment for staging and accepting

hot rolled In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. The concept is simil ...

coils of steel which have been hot wound at the end of a hot

strip mill The strip mill was a major innovation in steelmaking, with the first being erected at Ashland, Kentucky in 1923. This provided a continuous process, cutting out the need to pass the plates over the rolls and to double them, as in a pack mill. At t ...

or hot rolled plate mill. Also included in a typical temper mill installation are pinch rolls, a leveler (sometimes two levelers), a shear for cutting the finished product to pre-determined lengths, a stacker for accumulating cut lengths of product Sometimes a temper mill installation includes a re-coil line where the finished product is a coil instead of bundles of cut lengths of product. Maximum product flexibility capability could be attained if the installation was arranged to produce both coils and bundles of cut to length product. The heart of the temper mill is the cold rolling mill stand which produces the temper pass. It will include electric powered drive motors and speed reduction gearing suited to the process desired. The design of the rolling mill can be a 2-high or 4-high (even 6-high in some cases). The mill stand can be work roll driven or back up roll driven. The mill can be designed with hydraulic work roll bending or back up roll bending. Installations typically have a single rolling mill stand, but may have two. Pinch rolls provide back tension for the pay off reel in the entry section and entry and exit tension for the temper pass.

Function

The process goal is physical property enhancement through cold forming of the steel product in the bite of the work rolls. The physical properties that are enhanced by the temper pass due to elongation of the product include: * Dimensional trueness and repeatability * Suppression of yield point elongation * Improved product surface finish * Improve product shape and flatness * Decrease coil memory * Increase product yield strength * Develop proper stiffness or temper Typical elongation produced in the product is 0.5% to 2%. Product dimensions vary. Thicknesses include typical sheet metal gauges up to 1.00" thick plate. Widths vary from 36" to 125". The finish of the rolled product is controlled by using rolls having a variety of surface finishes designed to impart the desired finish to the product. Roll finishes range from ground and polished rolls to impart a bright finish, to shot-blasted or electric-discharged textured rolls that produce a dull, velvety finish on the steel surface. Typical auxiliary equipment includes PLC based controls, overhead traveling cranes, roll changing equipment, roll grinding equipment, hydraulic power unit(s), bundle lifting devices, Coil handling devices, etc.

References

{{cite book , editor1-last = Lankford , editor1-first = William T. Jr. , title = The making, shaping, and treating of steel , edition = 10th , year = 1985 , publisher = Association of Iron and Steel Engineers , location = Pittsburgh, Pennsylvania , ISBN = 0930767004 , lccn = 84081539 Steel Metal forming