Hot-rolled steel is processed at a very high temperature over 1.700 °F or about 926 °C, which is above the temperature required to recrystallize most steels. This makes the steel easier to form and results in products that are easier to work with or weld. It is a less expensive process than cold-rolling but not suitable when tight tolerances and precise results are required. It is, though, a good option when material strength is important and the surface finish is not a major concern.
Hot-rolled steel products are uncoated and have excellent weldability, good ductility, and most are produced with guaranteed minimum yield strengths. Uncoated hot-rolled steel is particularly well suited for applications that require hot-dip galvanising as a finish. Products may also be supplied pickled and oiled or just pickled.
Australian Standards for Hot-Rolled Steel
BlueScope Distribution can supply hot-rolled steel sheet in accordance with the dual Australian/New Zealand standard, AS/NZS 1594: 2002 (reconfirmed without changes in 2016) Hot-rolled steel flat products, AS/NZS 3678:2016 Structural steel – Hot-rolled plates, floorplates and slabs, and AS 1548-2008 (R2018) Fine grained, weldable steel plates for pressure equipment.
The standard specifies the requirements for hot-rolled carbon steel produced on a continuous mill in widths up to 2 m and thicknesses up to 8 mm for formability and extra-formability grades, and 16 mm for other grades. The aim of the standard is to ensure the steel will meet the needs of users wanting to use it for steel plate, floorplate, steel and strip, particularly in terms of material requirements and dimensional tolerances.
AS/NZS 1594: 2002 (R2016) includes slit material with a parent material that has an “as-rolled” width of at least 600 mm.
The standard allows for a number of different grades of steel produced by hot-rolling, with the following requirements:
- For analysis grades – specifications only for chemical composition.
- For formability, extra-formability, and structural grades (including those that are weather-resistant) – specifications for chemical composition as well as mechanical properties.
- For floorplate – specifications for chemical composition and mechanical properties.
Hot-rolled steel that is suitable for structural steel plates, floorplates, and slabs is produced in accordance with AS/NZS 3678. The standard specifies requirements for manufacturers of these products to ensure they will be suitable for both general structural and engineering applications. Type testing, minimum production testing, as well as inspections and resultant test certificates are required.
Steel plate for pressure equipment including vessels and boilers is produced in accordance with AS 1548, which specifies requirements for hot-rolled, fine-grained carbon-manganese steel plates up to a thickness of 150 mm.
Product Groups for Specific Manufacturing Requirements
There are three different categories of hot-rolled steel to meet customers’ requirements:
- Analysis products
- Structural products
- Formable products
In addition, the company produces a range of hot-rolled, enhanced weather-resistant steels for non-industrial and non-marine environments in thicknesses from 3 to 6 mm. Similar cold-rolled weather-resistant products are also available in thicknesses that range from 1 to 2 mm.
Formable Steel
Formable products can be supplied by BlueScope Distribution are hot-rolled and are designed for bending, pressing, and for drawing applications.
There are six grades all of which have good to excellent weldability and formability, and guaranteed chemical compositions. Some grades have guaranteed minimum yield strengths. All have a mill edge that may be trimmed and all are available picked and oiled or just pickled if required.
- HA1 is available in widths up to 1.55 m and in a thickness range from 1.6 to 12.7 mm.
- HA3 is available in widths up to 1.55 m and in a thickness range from 1.8 to 6 mm.
- HA4N is available in widths up to 1.2 m and in a thickness range from 1.6 to 12.7 mm.
- XTRAFORM® 300 is available in widths up to 1.25 m and in a thickness range from 1.55 to 6 mm.
- XTRAFORM® 400 is available in widths from 800 mm to 1.35 m and in a thickness range from 1.6 to 6 mm.
- XTRAFORM® 500 is available in widths from 850 mm to 1.25 m and in a thickness range from 2.5 to 6 mm.
Typical uses are diverse, ranging from automotive components, mower parts, and agricultural machinery to furniture and brackets.
Weathering Steel
Weathering steel products have a distinctive, almost rusty looking patina that forms as a result of constant exposure to the atmosphere. Products are widely used for building bridges and manufacturing shipping containers and rolling stock. Because of its aesthetic qualities, weathered steel is also used for building facades and for decorative sound barriers on freeways and motorways.
Contact the team at BlueScope Distribution to discuss your specific needs for uncoated hot-rolled steel.
Analysis Steel
Analysis products can be supplied by BlueScope Distribution are hot-rolled and have chemical compositions specified in AS/NZ 1594 that are guaranteed by the company. This type of hot-rolled steel is typically used in hot water systems, including for parts that are vitreous enamelled, and for the manufactured of cylinders, including gas.
There are seven different grades, all of which offer good weldability and a surface that is excellent for galvanising applications. All hot-rolled analysis products have a mill edge that is trimmed.
- HA1006 is available in widths up to 1.55 m and in a thickness range from 1.55 to 12.7 mm. Available pickled and oiled or just pickled.
- HA1016 is also available in widths up to 1.55 m and in the same thickness range (1.55 to 12.7 mm). Available pickled and oiled or just pickled.
- HXA1016 is available in widths from 1.151 m to 1.55 m in a thickness range from 3.5 to 12.7 mm. Available pickled and oiled or just pickled.
- HA1010 is available in widths up to 1.55 m in a thickness range from 1.5 to 12.7 mm. Available pickled and oiled or just pickled.
- HK1042 is available in widths from 1.351 to 1.45 m in a thickness range from 3 to 8 mm.
- HK10B55 is available in widths from 876 to 975 mm in a thickness range from 2 to 4.5 mm.
- HXK15B28 is available in widths from 801 to 900 mm in a thickness range from 2 to 8 mm.
Structural products manufactured by BlueScope Distribution are hot-rolled and have guaranteed minimum yield strengths. Typical uses range from structural sections, tanks, and gas cylinders, to light poles, shelving, guardrails, and industrial shelving.
Structural hot-rolled steel is available in six grades, all of which offer excellent weldability. BlueScope Distribution’s structural products are also perfect for galvanising applications. All are supplied with a milled edge that may be trimmed if required.
- HA200 is available in widths up to 1.55 m and in a thickness range from 1.6 to 12.7 mm. Available pickled and oiled or just pickled.
- HA250 is also available in widths up to 1.55 m and in a thickness range from 1.6 to 12.7 mm. Also available pickled and oiled or just pickled.
- HA250 floorplate is available in widths from 1.2 to 1.55 m and in a thickness range from 2.1 to 8 mm.
- HA300 is available in widths up to 1.55 m and in a thickness range from 1.6 to 12.7 mm. Available pickled and oiled or just pickled.
- HA350 is available in widths up to 1.55 m and in a thickness range from 1.5 to 12.7 mm. Available pickled and oiled or just pickled.
- HW350 is available in widths up to 1.2 m and in a thickness range from 3 to 6 mm.