Precision microanalysis of B toward actualization of welded structure using B doped Al-Si-Mn weathering steel

Al-Si-Mn weathering steel is a promising material for long-life social infrastructure. This steel shows excellent weathering ability without rare elements. When this steel is applied to welded structure, toughness at HAZ (Heat Affected Zone) bond in weld joint drops. It is becoming clear that doping of B at ppm-level to the steel improves the toughness, but the effective range of B content is limited. So precision quantitative microanalysis of B for control of the effect is necessary. In this study, we applied laser ablation ICP mass spectrometry (LA-ICP-MS) to precision microanalysis of B in the steel. This method is rapid process in comparison with various wet chemical analyses which are prescribed for quantitative microanalysis. The values of B ion intensity by LA-ICP-MS are correlated closely with B concentration by wet chemical microanalysis. This excellent correlation suggests LA-ICP-MS is a promising method for quantitative microanalysis of B in Al-Si-Mn weathering steel.