SWITCHING STAINLESS GRADES FOR EXISTING PRODUCTS CAN BE A DIFFICULT TASK 

Since the price of nickel doubled to over $US17,000 per tonne a few months ago there has been much talk of substitution – using nickel-free or low-nickel grades of stainless instead of type 304 and other austenitics. This is not a new trend. Whenever nickel costs increase, mills and end-users examine the possibility of switching in this way. However, in our experience, diverting to a different grade is far from straightforward. It may look superficially attractive in terms of cost per tonne, but the mechanics of making the change are complicated. 

For each specific end-use application, trials must be made to see whether the alternative material meets the requirements of the job. This covers not only the obvious criterion of corrosion resistance, but also qualities such as tensile strength, formability, work-hardening and weldability. Regulatory approval for a change may have to be obtained where the material’s end-use is subject to strict performance guarantees on the grounds of safety or environmental protection. This all takes time.

In many cases a full life cycle analysis will show that alternative materials, while cheaper initially, can ultimately prove more costly because they will need replacing sooner. Moreover, while all these tests, studies and analyses are being conducted, the stainless market may well have turned and the cost of 304 will have gone back down. Hence large-scale switching to a low-nickel material with a lesser specification rarely takes place.

The International Stainless Steel Forum recently conducted a survey which showed that its members’ production of the 200 series of stainless types rose to about 1.5 million tonnes in 2003. But the austenitic chromium-manganese materials still accounted for only 7.5 percent of total stainless output. It seems the low-nickel grades are not taking any significant share of the market away from 300 series which accounted for over 70 percent of production last year.

Stainless consumption maintains its steady growth trend of 5 percent per year on average, in spite of the dire warnings that price volatility will harm demand.

Source: MEPS - Stainless Steel Review