A breakthrough has been made in the production of special bar quality (SBQ) steel at Iscor's Newcastle works in Kwazulu-Natal, which will see a boost in production of this high-value added steel.

 

A loss-making activity until February this year, SBQ steel production is now set to become a significant contributor to the plant's income.

"We aim to produce 3 000 t of SBQ steel a month initially and will gradually increase production with the aim to put out 20 000 t a month by the end of next year" Iscor Newcastle general works manager: operations Johan Fourie tells Engineering News exclusively. Previously the plant produced around 2 000 t of SBQ steel a month with difficulty.

 

Dr Eloy Martinez , formerly of Swiss continuous-casting machine manufacturer Concast, was called on to assist in finding a solution.

The basic process was retained, but incorporates a number of adjustments. Delays caused by blockages resulting from alumina and calcium sulphide build-up in caster nozzles have been eliminated, enabling continuous casting of larger volumes and ultimately cost-effective production.

 

The adjusted process was introduced in February following the completion of the last successful test runs.   "Once production reaches 20 000 t a month, SBQ steel sales are anticipated to generate around 25% of the Newcastle works' turnover.", comments Fourie.

SBQ grades from  Newcastle works are sold in the automotive and mining sectors of the domestic market,  while the greater portion of all SBQ sales are in the form of exports to  Australia and the UK.

 

Newcastle works now  aims to increase its share in  the the local and foreign markets, focusing on the automotive sector, but also on other markets where SBQ steel is used in large quantities, such as in grinding mill rounds in the mining sector.

The US and UK are targeted as initial potential foreign markets while plans are   to enter the Asian market  when its economy recovers.

SBQ steel grades fetch prime prices on the international market.

 

A commercial billet, for instance, fetches US$150 a ton at present while an.SBQ product will fetch US$250 a ton or more, depending on  the grade and profile.

Iscor Vereeniging was  previously the only local producer of grades of steel  similar to SBQ, while the balance was imported by end-users in the form of final components.

 

With Iscor's Vereeniging works supplying a significant portion of similar SBQ steel grades to the automotive industry, Newcastle works will produce and supply other grades and is able to produce larger profiles of SBQ steel.

Iscor's policy of import parity pricing applies to all its steel, including SBQ grades, and now with the quality in place, Newcastle is focusing on perfecting service so as to offer a more attractive package to users who currently import SBQ steel.

As a result of ineffective production methods used before, Iscor Newcastle had been selling SBQ steel at a loss - therefore, the reduction in production cost, which was effected by the breakthrough, will not translate into reduced prices for customers.

However, the advantage is passed on to the customer as the ability to produce larger volumes will enable bulk purchases, which are discounted.

 

The breakthrough will also ensure that Newcastle works stays in the SBQ market.

Elaborating on the break-through in the process, Fourie says the Newcastle team is proud of the achievement.

"With a fairly sophisticated chemical composition the production of quality SBQ steel is a challenging task and there are only a few producers in the world that have succeeded in this."

SBQ steel comprises normal carbon and alloy steels but it is aluminium-killed instead of silicon-killed as is the case with other commercial steels.

 

Sulphur is added to ensure machineability.

Previously  problems were experienced in the casting process, as a build-up of alumina occurred in the caster nozzles, eventually causing a total blockage. This resulted in frequent and costly delays in the process. The build-up can be controlled by adding calcium.

However, this chemical would react with the sulphur in the steel to form calcium sulphide which also causes blockages.

Martinez has assisted in determining the correct quantities, logistics and rate of calcium addition involved in the process. Despite the dramatic increase in production, additional capacity is not required, as the increased production of SBQ steel will replace commercial steel production.