Intergranular Corrosion Investigation & Testing

Materials testing and analysis forms the core of our business. One recurring investigation involves the cause and effect of corrosion of metals. 

The effects of corrosion can be both beautiful and costly and here at BBB Technologies forensic materials laboratories, we routinely investigate the cause and mechanism of corrosion, and if a liability exists, establish where it lies. We also commonly advise on corrosion protection, particularly in structural steel applications.

If it is not prepared for and managed correctly, corrosion process can begin and propagate rapidly, potentially causing significant damage.

In a most recent case we were asked to investigate the failure of a welded stainless steel feed pipe at an industrial plant. During welding, there is a significant heat affected zone on the periphery area of the weld. This localised heating can cause subtle changes to the structure of the steel within the heat affected zone. 

Using metallographic micro-sectioning of the pipe, we found that within this heat affected zone, chromium carbides were segregated on the grain boundaries. The result was that localised depletion of chromium within the steel microstructure. Chromium is the element that makes the stainless steel "stainless", and this absence of chromium led to localised intergranular corrosion which had taken place during the initial acid pickling of the steel. 

In all aspects of corrosion investigation from dezincification to spongiosis, our forensic experts are available to investigate the issue at hand. Our corrosion experts are available at short notice. Contact us today.