Across InfraBuild’s operations, we are committed to a process of Continuous Improvement – it’s part of our values. For our Steel Mills, this means the nonstop pursuit of streamlining processes towards more sustainable operations and manufacturing excellence.
Both Victorian and NSW Steel Mills are constantly looking for areas requiring improvement in the steelmaking and manufacturing process. “By streamlining processes, we can make gains in both production efficiencies and cost savings,” explains InfraBuild’s Executive General Manager of Manufacturing, Shane Murphy.
Two recently announced improvements at the Laverton Steel Mill in Melbourne and Sydney Steel Mill at Rooty Hill will have flow-on benefits, improving operational efficiencies and minimising wastage for the business.
Laverton Rod Mill: improving finishing end speed and throughput
At Laverton’s Rod Mill, a long-term bottleneck in the manufacturing process was the finishing end. The problem was the number of hours generated each year through trestle availability delays.
Head of Victorian Rod and Bar Manufacturing, Hercules Van De Merwe explains, “as the Laverton Rod Mill is a single strand mill, all coils produced must be tied by one tying machine. The speed of this machine determines the throughput of the mill in a number of sections. Consequently, speeding up the tying machine leads to an increase in the throughput of the mill, by reducing the trestle cycle time.”
Through the Six Sigma DMAIC (Define, Measure, Analyse, Improve, Control) methodology, the team tasked with addressing the issue identified opportunities for improving the finishing end process.
Reviewing footage gave the team insights into actual process equipment times, while smart pressure transducers also provided process feedback. This resulted in significant step-change throughout the process, and with IO-Link sensors the team were able to optimise the tying machine process, and therefore reduce the cycle time.
The optimised process has reduced the tying machine cycle time from 79.5 secs to 73 secs, resolving the bottleneck at the rolling product finishing end. The result is a minimisation in delays and an improved capacity.
Sydney Meltshop breaks mould life record in a 5-year Continuous Improvement project
A further Six Sigma project at the Sydney Steel Mill was to extend the life of precision-made copper moulds, which are part of the steelmaking process.
The billet caster pours molten steel into these moulds, which causes a frozen steel skin to form around the liquid core of the continuous strand, like the frozen outer shell of an ice cube.
Over the past five years ongoing efforts have been made by the Sydney Melt shop to improve the life of these high-cost consumable moulds. The benefits would be cost savings and reducing caster downtime for change-outs.
The team identified several opportunities and solutions, from changing the type of mould lubricant, to installing flow meters to fine-tune mould lubricant use. The team also trialled different suppliers for mould copper tubes and implemented the use of a mould measuring device on every down day to ensure the taper profile remained to specification. These measures, combined with continuous good operational control by shift crews, has resulted in significant benefits.
Overall the copper mould process is more sustainable: the improvement in mould life has led to lower consumption, and sourcing from a new mould supplier has contributed to savings. In the 2020-2021 financial year, 40 mould tubes were used compared to 81 in FY19-20. It’s anticipated there will be an increased benefit for FY21-22 in savings both from a sustainability and maintenance point of view. In addition, a lower strand breakout rate has also been observed.
The benefits of this project are clear when comparing mould life over the past five years: The average mould life in FY2015 was 161 heats. The average mould life in FY2021 was 573 heats and has continued to improve: our current average mould life in FY21-22 is 766 heats. And a mould life record was achieved in September this year of 1026 heats.
For both InfraBuild Steel Mills the ongoing Continuous Improvement strategy has become an essential.
“Steel making is a competitive industry with global production of around 1 billion tonnes across many countries and so continuous improvement is vital to maintain an edge over our competitors. If we fail to improve we fall behind,” says Head of NSW Rod and Bar Manufacturing Steve Elliott.
And what do the gains mean for manufacturing in the InfraBuild business?
Steve explains, “Continuous Improvement, means lower costs, reinvestment, improved profits and a sustainable future for the manufacturing business in Australia. ”
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