|Corrosion causes an enormous damage. In average each tenth blast furnace works for "covering the corrosion expenses". Substances that decrease the rate of metal oxidation are called corrosion inhibitors. Under certain circumstances, small concentrations (10-5 mol/L) of pertechnetates, the salts of pertechnetic acid HTcO4 can protect iron and carbon steels from corrosion. However the radioactivity and expensiveness prevent them from using in industry, a very annoying fact especially because manganese and rhenium salts do not have such ability.|
Another unique property of 99.9%-purity metallic single-crystal technetium is its type II superconductivity at relatively high temperature, at 11.2°K. It implies that technetium alloys may turn out to be ideal superconductors.
Scientific significance for astronomers: The discovery of spectral lines of technetium in red giants spectra was a landmark in stellar nucleosynthesis theory.