Mpumalanga Business 2020-21 edition

steel work, chimney stacks, ducting, roofing and
cladding (most commonly poultry and piggery
buildings), walkways including grating, hand rails,
stairs, electrical boxes and security fencing. It is
also widely used in sewage processing plants and
municipal water storage tanks.
Mpumalanga boasts a wide variety of large
industries, including power generation, mining,
farming and manufacturing. To support these
diverse industries throughout South Africa, the
steel industry lies at the helm. Stainless steel has
proven itself as a multi-functional and adaptable
metal of choice and has proven successful and
offers great value to the manufacturing industry.
The manufacturing industry as a whole is under
great strain, especially in this tough economic
climate. With this in mind, one has to consider the
financial attributes of any project, structure or
equipment. Life-cycle costing is therefore an
invaluable tool that takes into consideration the
initial material cost, fabrication costs, maintenance
and refurbishment costs, lost production costs
due to downtime and possible replacement cost
over a defined product’s lifespan. Stainless steels
generally have higher input cost compared to
some competing materials, yet they are proving to
be the most cost-effective long-term choice. The
case study related to coal rail wagons in the South
African market clearly illustrates these principles.
Case study: coal wagons
In 1985, trial coal wagons were manufactured out
of 3CR12 material in the hot rolled and annealed
(HRA) surface finish. These wagons are used to
transport coal between Ermelo and Richards
Bay. They have a payload of 80 tons and make
the journey roughly five times a week. Before
3CR12, the wagons were made from Cor-Ten,
but these only lasted 8-12 years, with refurbishment
required after five years.
Over the years, inspections of these coal wagons
have been conducted after 27 years of service.
Such a study was done in 2012. The wall thickness
of these coal wagons was measured using accurate
ultrasonic measurement equipment. The mild-steel
wagons recorded corrosion-abrasion wear loss of
160 micrometres per annum (160μ/yr). This is
attributed to the surface rust or iron oxide being
removed, exposing fresh steel. The fresh steel in an
oxidising environment reverts back to its natural
iron-oxide state, forming a continuous corrosion
cycle. Compared to mild steel, stainless steel forms
a very thin, tenacious oxide layer which gives it its
characteristic corrosion resistance. The metal loss
of 10μ/yr was recorded for 3CR12 wagons in this
application. From these measurements, 3CR12 coal
wagons in this environment have a predicted total
life of 65 years. Mild-steel wagons would have to be
replaced eight times in this time period, increasing
costs and potential lost production time.
As the country grapples for sustainable
infrastructure development for the future in
energy, water and sanitation, transport, digital
infrastructure, human settlements, agriculture and
agroprocessing, stainless steel is the material of
choice due to its durability, low maintenance and
sustainability.
Columbus Stainless is proud to have contributed
to the development of this material over five
decades and will continue to do so as Africa and
the world continues to grow. Indeed, the future of
manufacturing is Stainless. ■
31 MPUMALANGA BUSINESS 2020/21