Effect of Sampling Methods on N Detection in High Nitrogen Steel

Abstract

The effect of sampling methods on the detection of N content in the high nitrogen steel (HNS) was studied by variance analysis method. In the experiments, two kinds of samples (rod sample and chip sample) were chosen. It was showed that when the N content was in the range of 0.06%∼0.4%, the results obtained by two methods were almost the same, indicating that both were suitable to identify the N in the steel. However, when the N content was higher than 0.4%, the result obtained using chips as sample was lower than that using rod. The N2 bubble in the rod sample might cause error since it didn't comprise the N content. Hence, the N content could be reflected more accurately by the chip samples. Based on the difference of N content detected by two methods, the shrinkage rate was analyzed theoretically and found to be inversely proportional to the pressure of N2 bubbles in steel.

Effects of Salt Tracer Amount, Concentration and Kind on the Fluid Flow Behavior in a Hydrodynamic Model of Continuous Casting Tundish

“…However, some researchers focus on finding new experiment methods or optimizing the existing methods, since the obsolete experiment methods are sometimes inaccurate. For example, Zhang et al1, 2 and Ericsson3 investigated the filling process of sampler and effect of sampler type on the inclusion characteristics determination, respectively; also Li and Chu4 studied the method of nitrogen detection in high nitrogen steel; in addition Michelic et al5 proposed a method for inclusions analysis with special regard to the measured sample area; furthermore Kanbe et al6, 7 developed an Extreme Value Distribution method for large inclusions analysis. Similarly, the hydrodynamic modeling method that widely used to simulate the fluid flow will be reconsidered and discussed in this paper.…”