Preparation Of Ceramic Lined Steel Pipe Composite By Gravitational Separation SHS Technique

With the high development of industrial technology, metallurgy, mining, chemical and energy sector requires a lot of wear-resistant, corrosion-resistant and heat-resistant pipe materials. Traditional pipe have not been meet well with these requirements. Ceramic lined steel pipe composite by SHS technology has not only good wear resistance, heat resistance, but also excellent corrosion resistance, so it has extensive application prospects.In this paper, Ceramic lined steel pipe composites were prepared by gravity separation SHS method using Fe2O3and Al powder as the main raw material, SiO2, Na2B4O7, TiO2as additives. Compressive shear, corrosion resistance and thermal shock tests were investigated to evaluate the properties of samples. The phase compositions of the ceramic layer were analyzed by XRD. Microstructure of the coating was observed by SEM. The following conclusions were obtained:(1) By thermodynamic calculations, it is found that there is a critical ratio of materials and steel in the process of preparing ceramic lined steel pipe composites. The relationship among the ratio filling density and the inner pipe, outer diameter is derived by calculating. In this experimental condition, the critical ratio is0.5627and filling density is1.68g/cm3. And the best filling density of this experiment is1.6g/cm3by analysis and comparison.(2) With adding2%amount of SiO2, the bulk density of ceramic coating is the largest, and can be reached3.43g/cm3.(3) Na2B4O7additive could improve the compressive shear strength of ceramic lined steel pipe composite significantly and promote the density of coating. The best adding amount of Na2B4O7is4%.(4) TiO2additive can promote sintering behaviour of Al2O3and reduce temperature range of ceramic solidification. Ti elements can promote the wetting behavior of ceramics and iron and increase the compressive shear strength of ceramic lined steel pipe.(5) Moderate excess of Al powder can reduce the content of Fe-Al spinel (Al2O3·FeO) phase, contributing to improve the corrosion resistance of ceramic lined steel pipe. In this experimental condition, the composite pipes would reach the best performance when the excess of Al powder is3%.(6) Appropriate amount of additives can improve the thermal shock resistance of composite steel pipe; composite pipes could have the best thermal shock resistance with6%TiO2adding.