Advanced welding technologies are transforming resource utilization and sustainability in high-cost industries. Techniques such as submerged arc welding (SAW), cold metal transfer (CMT), and laser welding allow for accurate repairs that minimize material removal, extend lifespan and reduce environmental impact. This shift from replacement to repair is in line with sustainability goals by supporting the circular economy, minimizing waste and promoting local repair services.
Consider the notable contrast between disposing of smartphones and decommissioning industrial machinery.
Even when it works perfectly, smartphones are often replaced prematurely due to fashion trends. In contrast, industrial machinery, which consists of large components such as shafts of 20-30 tonnes, requires a more sustainable approach.
Disposal and replacement of these components requires important energy and resources for smelting, manufacturing and transportation, which often need to be imported.
Conversely, repairs often involve adding several kilograms of welding material and extending the service life of the components for more than a decade.
Localized locomotive repairs can be a turning point for the rail
A prime example of the success of this approach in South Africa is seen in the repair of locomotive crankshafts.
When the crankshaft is worn excessively, these important large components, up to 4 meters long in a 16-cylinder engine, over 2,200 kW, have previously been completely replaced and usually replaced by imports from the US.
Local engineers developed and tested Arc Microwelding (SAMW) technology that was submerged in the early 2000s, minimizing thermal input and distortion and successfully repaired these crankshafts with incredibly proven reliability and zero-file records.
In particular, the original equipment manufacturer initially resisted this repair method and feared a loss of revenue.
Transnet approval
However, rail operator TransNet approved the process, recognising the value and functionality of the repaired crankshaft.
This successful venture not only reduced repair costs for the rail industry, but also promoted local expertise and reduced reliance on imports.
Based on this success, welding repair technology has expanded to include a wide range of industries, from repairing small pumps to renovating huge turbines for the power generation sector.
The key is to select the most appropriate welding technique for each repair, minimizing invasiveness, and ensuring that the repaired components function just as effectively as the original.
Overcoming traditional welding challenges
Historically, welding was perceived as an offensive process, whereas high-thermal inputs lead to distortion and potentially inferior components.
However, advances in welding technology have alleviated these challenges.
Techniques such as SAMW that minimize thermal input and distortion have now been able to repair previously thought irreparable components.
Currently, there is a welding technique that strengthens components with the same fatigue life after repairing welding.
Such innovations not only reduced repair costs, but also gave the power to localize important maintenance tasks that South African industries had previously relied on imports.
CMT has opened up more opportunities
The emergence of CMTs and laser welding further expanded the range of repairable ingredients with even lower thermal inputs.
These technologies allow for accurate repairs with minimal thermal zones, minimizing the risk of material inclusion, further reducing distortion and ensuring the integrity of repaired components.
In addition to extending equipment lifespan and reducing material costs, these advanced welding technologies also contribute to improving operational efficiency.
In high value rotating equipment, traditional welding methods can introduce stress and distortion that lead to early failure, but by adopting more sophisticated technologies, the industry can minimize downtime and ensure the continuous, reliable operation of critical machines.
It brings environmental impact and sustainability to new heights
The environmental benefits of this repair-centric approach are important.
Replacing large components requires extraction, processing and transport of raw materials, resulting in substantial carbon footprint.
In contrast, repairs often use minimal material usage, significantly lower energy consumption and reduce overall environmental impact.
Laser welding technology has immeasurable promises in the future.
Laser welding allows for very accurate repairs with minimal distortion, further expanding the range of repairable components.
Robots to rescue
The integration of robotics and automation further increases accuracy and efficiency while minimizing associated operational risks and minimizing waste.
Advanced welding techniques are not just tools for repairs. They are key enablers of resource conservation and sustainability in capital-intensive industrial machinery.
By embracing a repair-oriented approach and leveraging innovative technologies, South African industries can increase operational efficiency, reduce environmental impacts, and contribute to a more sustainable and resilient industrial landscape.
