History:
In 1963, Middelburg, Transvaal, was chosen as the site for a plant to produce ferro-chromium entirely from South African raw materials. Production commenced in 1964. In 1965 Southern Cross Steel was built at the same site, creating a unique and totally integrated speciality steel manufacturing unit.
Production Capacity:
The existing stainless steel production facilities at Middelburg have a finished production capacity of about 19 000 tons a year of hot rolled plate, and around 4 000 tons a year of cold rolled sheet – a total of 23 000 tons.
The current R150-million extensions to the mill will ultimately boost the production of semi-finished stainless steel products to 200 000 tons a year. The mill – one of the most advanced in the world – has been designed in such a way that production capacity can be further increased when necessary by the relatively simple addition of various modules.
Financial:
Southern Cross Steel is a division of Middelburg Steel and Alloys (Pty) Ltd., which is 72 percent owned by Barlow Rand.
Current turnover is about R150-million. The new mill capacity is expected to boost turnover to about R500-million, while sales of 3CR12 are expected to generate additional turnover in excess of R1000-million by the early 1990’s.
3CR12
The designation is readily understood by steel engineers. It means: A chromium containing corrosion (Three “C’s”) resisting steel. The “CR” of course refers to chrome, while the 12 refers to the amount of chrome contained in the steel, that is, 12 percent. The “3” also refers to the amount of carbon in the steel (0,3 percent) [sic].
Thus, 3CR12 is a 12 percent chromium containing corrosion resisting steel. It is not a stainless steel and is not designed to replace stainless steels.
Rather, it is designed to fill the price and “technology” gap between stainless steels at the top of the market, and rust-prone carbon steel at the other end.
3CR12 is a highly sophisticated steel which required 10 years of research and development to develop the qualities of weldability and toughness. The sophisticated equipment at the new mill will enable Southern Cross to produce the steel in the large volumes necessary to meet the projected demand.
The Breakthrough:
Thin sheets of this type of steel have been used for many years elsewhere in the world in applications such as exhaust mufflers. But the heavy plate market has been denied the use of this steel because of welding problems.
The Southern Cross breakthrough centred on the development of a 12 percent chromium containing corrosion resisting steel in plate form (3,5 mm to 20 mm), which is weldable. This opens the door to the massive industrial market where coated carbon steel and corrosion protection systems are currently in use.
Consumption of the steel – designated 3CR12 – is expected to reach more than one million tons in South Africa alone by the early 1990’s worth more than R1 000-million at today’s prices. The additional offtake potential on world markets is far greater.
Southern Cross managing director John Hall comments: “The implications of this technological development are simply too big to accurately quantify at this stage. Research, development, prototype tests and feedback from potential users both in South Africa and overseas indicate that we’ve got a tiger by the tail – but it is still too early to make specific forecasts.”
Professor Paul Robinson, professor of corrosion science and engineering at the University of the Witwatersrand, who has been associated with the development work on 3CR12, echoes the enthusiastic predictions about the steel’s future.
“It is a very exciting development which has major implications for those areas of industry which at present rely heavily on galvanised steels or coated mild steels.”
Professor Robinson said that it is no exaggeration to describe 3CR12 as one of the most overdue industrial developments of the century.
The new steel is designed to fill the gap that exists between rust-prone carbon steel and conventional stainless steels which cost three times and more per ton than carbon steels.
It is estimated that about half the total world consumption of carbon steel, currently running at around 650-million tons a year, is wasted on corrosion-linked replacement. To combat this, vast sums are spent on maintenance and on devising and applying costly corrosion-resisting coatings, with limited success.
By contrast, 3CR12 is a chromium containing steel which enjoys inherent corrosion-resisting properties and thus requires little or no maintenance. More-over, its price makes it competitive with carbon steels treated with special protective coatings.
Hall explains: “In appropriate application areas, particularly industrial corrosive environments, 3CR12 will outperform any other economically comparable material.”
Development of a similar steel elsewhere in the world has been inhibited by the fact that stainless steel producers tend to go up-market to more exotic steels in order to obtain a greater return per ton of output. Carbon steel producers, on the other hand, aim at down-market, lower alloy steels because of the difficulties and cost involved in high-technology steel manufacture.
But the prime motivation for the ten years of research and development which led Southern Cross to its success with the new steel lies in the company’s ready access to South Africa’s vast chrome reserves – about 80 per cent of the Western World’s total – and its expertise in beneficiation.
3CR12’s research and development was boosted by valuable collaboration with the Universities of Cape Town, Pretoria, and the Witwatersrand, the CSIR, the National Institute of Metallurgy, the Chamber of Mines and the South African Bureau of Standards.
Some 500 prototypes are currently being tested in a wide range of mining, chemical and heat-resisting applications throughout South Africa and in Britain and Australia. Protype tests are also planned for Germany.
Recent successes in a number of prototype areas – notably in the gold and coal mining industries – tied to the completion later this year of the R150-million extensions to the Southern Cross mill in Middelburg, have poised 3CR12 for its impact on local and international industry.
