| The anti-thermal shock of Mg-PSZ tube is one of the most important technologies in the probe for monitoring oxygen dissolved in molten steels. It directly affects the quality of monitoring oxygen. And the anti-thermal shock of Mg-PSZ tube is concerned with its ingredients, impurities, crystal grain size and distribution of its phases. The powder of 8.3mol% Magnesia partially- stabilized zirconia (Mg-PSZ) has been prepared by coprecipitation method. The active ingredient control of ZrOCl2, the relationship of MgO content in powder and pH value of solution, the effect of parameters of washing and ball mill for size and composition of the powder and the impact of calcining temperature to the residual Cl- have been discussed in the process of Mg-PSZ powder preparing.φ10mm column's specimens have been produced by dry-press. And the sinter process and heat-treatment process of the specimen were explored. X-ray diffraction analyses have been carried out to study the phases in quality and quantity. Scanning electron microscopy observations and dilatometry have also been performed. At last, the Mg-PSZ powder was shaped into tubes by injection machine. And the tubes treated with technics that had been explored were tested in the lab and then the tubes were assembled into oxygen probe and were tested in the Wuhan Iron and Steel.Experiments suggest that samples sintered at 1700℃for 2 hours have enough density and suitable phases. There were lots of m-phases in all samples heat-treated by two steps. But in the samples heat-treated by one step , heat treatment at 1100℃for 2 hours, the m-phases distributing around and in the c-phase matric took up 61% and the grains were very fine, and this sample's dilatometric curve changes smooth. But the m-phases in the sample treated at 1300℃attained to 94%, and its dilatometric curve had a sudden decline in the m-phase transforming area. The thermal experiment and the field test both also confirmed the former was better.
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