This standard specifies a method for the determination of sulfur content in steel and alloys using the potassium iodate Titrimetric method after combustion in a tube furnace. Suitable for iron, steel, superalloys and precision alloys with sulfur content ranging from 0.0030% (m/m) to 0.20% (m/m). Samples and fluxes are oxidized in a tube furnace at 1250 ° C to 1350 ° C. The sulfur is completely oxidized to sulfur dioxide. After the generated sulfur dioxide is absorbed through the acidic starch solution, titration is performed using the potassium iodate standard solution. The sulfur content is calculated according to the volume of the potassium iodate solution consumed. This method is suitable for high-precision determination of sulfur content. It requires high purity of reagents. The operation requires strict control of oxygen purity.