Gives steelmakers a means to quickly and accurately measure hydrogen content in molten steel on the operating floor. A probe is immersed, nitrogen carrier gas is pumped through a bubbler tube and collected in a porous ceramic bell which permits the passage of the gas but not molten steel. The hydrogen in the solution in the steel is diffused into the carrier gas and collected in the bell. The gas is bubbled through the steel and around the closed system for a number of cycles, as an equilibrium is established between partial pressure of the hydrogen in the steel bath and the gas. The hydrogen partial pressure in the gas is measured on-line by a thermal conductivity detector. When the circulating gas reaches equilibrium with the melt, and there is no further pickup of hydrogen, a stable plateau is detected and hydrogen content is displayed.
Applicable for ladle, tundish and ingot mold measurements for direct process control in steelmaking.
Features and Benefits
Sampling methods are inherently time consuming, difficult, require a high degree of operator skill and, even when great care is taken, prone to error as hydrogen may be lost or picked up during the sampling procedure. All of these drawbacks are eliminated as no solid sample is needed and the immersion test is simple. Both the success rate of immersion tests and the reproducibility of analysis results are exceptionally high. Measurement results are consistent with thermodynamic data, display a good correlation with the best laboratory sample analysis, and are accurate over the range of hydrogen content normally found in steelmaking.