Intergranular boron segregation and grain boundary character in Alloy 304 austenitic stainless steel

Secondary ion mass spectrometry (SIMS) and orientation imaging microscopy (OIM) were used to study the relationship between boron segregation susceptibility at grain boundaries and grain boundary structure in Alloy 304 austenitic stainless steel containing boron as a trace solute impurity.; Boron segregation was detected at grain boundaries in materials heat treated at 1000 and 1100°C and both boron segregation and carbide precipitation were detected at grain boundaries in materials heat treated at 800°C. Coherent sum3 twin boundaries displayed high resistance to both boron segregation and carbide precipitation. sum1 (low-angle) boundaries displayed some resistance to boron segregation and high resistance to carbide precipitation. sum9 boundaries satisfying the Palumbo-Aust criterion displayed some resistance to both boron segregation and carbide precipitation. Other low-sum boundaries and general boundaries (sum > 29) displayed low resistance to both boron segregation and carbide precipitation.