Range of Grades
Bisalloy Steels produces the BISALLOY® range of quench and tempered performance steels across the three main product areas of high wear, high strength and armour grade specialty steels.
Our products are world class, with our structural grades complying with many of the world’s quenched and tempered steel plate standards.
While each grade has specific mechanical and chemical properties, the process information detailed below is applicable to all BISALLOY® steel products manufactured by Bisalloy Steels.
The technology used in the manufacture of BISALLOY® steel is not only world class, but the demands of high strength and high hardness steels dictate the need for one of the most stringent process routes utilised in the manufacture of steel plate, anywhere in the world.
Hot metal desulphurisation ensures low levels of sulphur and other impurities in steelmaking and vacuum degassing is carried out to reduce the hydrogen content of the steel, while also decreasing the amount of undesirable oxygen and nitrogen in the steel.
Control of impurities is additionally assisted through the use of hot metal injection and conditioning of the slag during the Basic Oxygen Steelmaking process.
Close control of chemical composition and final microstructure is maintained through the use of ladle refining with calcium injection, argon bubbling through the heat during steelmaking and alloying additions made under vacuum.
Following steelmaking, integrity of slab product is ensured by the use of electromagnetic stirring, continuous casting and controlled cooling of slabs prior to plate rolling.
Finally, plate rolling is carried out in a computer controlled four-high rolling mill in which each draft is modified during rolling for optimisation of final properties.
The net result is steel that provides improved toughness, structural integrity and fatigue resistance, providing consistent product performance in service.
Heat Treatment Process
Plate is heated in our natural gas fired furnace, prior to quenching in the Drever roller quench unit. Complete PLC control allows tight and consistent control of all furnace and quench operations, including water flow rates and pressure, furnace temperatures and residence times.
Pre- and post-heat treatment shot blasting removes scale and presents an attractive plate, resulting in improvements in product properties, welding and cutting, as well as simplification during fabrication.
The final operation is plate levelling, through our plate leveller, for material up to 32 mm thick. This has resulted in significant improvements in flatness of plate to market - much tighter than the Australian Standard and other International Standards.
Our quality assurance system ensures that full traceability exists from initial steelmaking right through the process to the final plate, with each plate individually hard stamped with a unique identification which links to the overall traceability.
All plates are tested for hardness, with structural grades tested in Bisalloy Steels’ NATA approved mechanical testing laboratory, and plates of all grades are certified.
The entire process is carried out in compliance with ISO9001, certified by Lloyd’s Register Quality Assurance (LRQA).
Each of the grades produced by Bisalloy Steels have been developed to optimise chemistry and mechanical properties in conjunction with our heat treatment process.
Our world class steel grades ensure that properties such as ductility, weldability and toughness are maximised, while also complying with the requisite hardness and strength requirements.
Continuous, committed research and development at Bisalloy Steels keeps our quenched and tempered steel product range at the leading edge of steel technology.
Already, we are developing steels to meet the emerging requirements for still stronger structural grades and these will be released to the market as demand dictates.