Melting erosion failure mechanism of tuyere in blast furnace

Abstract

In this paper, the common damage types of tuyere were sampled and analyzed. Specifically, the element content in tuyere was measured by Inductively Coupled Plasma Source Mass Spectrometer, Nitrogen-Hydrogen-Oxygen Analyzer, and Carbon-Sulfur analyzer. Then, Scanning Electron Microscope was used to analyze the microstructure of tuyere damage, and the element distribution of the damaged area was observed by Energy Dispersive Spectrometer. Finally, a metallographical analysis of the damaged location was carried out by an optical microscope. On account of those above analyses, the following results were obtained: firstly, the tuyere damage was mainly caused by erosion. After that, the grains at the hot surface and melting area of the tuyere were large, while those in the middle region were small. The content of the impurity element in tuyere nose increased, and the content of copper decreased. Moreover, there were two interfaces of slag-copper and iron-copper in the damaged area, and the Cu-Fe alloy was formed. At last, the failure mechanism of blast furnace tuyere erosion was explained in the paper.