The Preparation Of The Ceramic Stainless Steel Double-lined Steel Pipe

The steel pipe, while sending medium, apt to be worn out and corroded by the medium. It can be coated with wear-resisting, anti-corrosive interior lining, such as the ceramic-lined steel pipe, to lengthen the service life of the steel pipe. In order to strengthen the corrosion-resistant performance of the lined steel pipe, this paper carries on the study of the ceramic and stainless steel double-layer lined steel pipe.This paper uses ANSYS software to simulate heat transfer of the lined steel pipe. Adiabatic temperature is derived to be more than 2945K by algorithms. Through the thermal simulation, the condition under which the stainless steel layer metallurgy combines with steel pipe can be realized is deduced.This paper has studied the reaction activation of each oxidant in the thermite with Al by gravitational SHS experiments at first. The experiments show: When Cr2O3/CrO3=0.75, thermite reaction is comparatively steady, less sputtering, and Cr₂O₃ is transformed to Cr more highly;SiO₂ can partly react with Al and produce Si, causing the stainless steel layer containing a relatively high Si content;Cr₂O₃ content remaining in the ceramic layer decreases with the excessive percentage of Al in thermite increases;under Cr₂O₃/CrO₃= 0.75 and adding some additives, the sputter degree of centrifugal thermite reaction can be reduced;by solving deviation between the axis of steel pipe and centrifugal machine, lining's eccentricity can be prevented;adding SiO₂ under 2%, CaF₂ more than 4% in thermite, the quality of ceramic layer is the best;Al content remaining in the stainless steel layer is minimum when the amount of the Al in thermite is close to the chemical calculation amount,Using OM, XRD, SEM and ES, the composition and microstructure of the ceramic and stainless steel double-layer lined steel pipes have been analyzed. Stainless steel layer contains ferrite;The ceramic layer is mainly made up of A1₂O₃ and no FeAl₂O₄ exist in it. Also much analysis was laid on the metallurgy connection area between stainless steel layer and steel pipe.This paper has also studied the corrosion-resistant performance of stainless steellayer and ceramic layer. In the polarization curve of stainless steel layer in 0 .5mol/L H2SO4, there is a wide passivating region that the width is 0.532V, and the passivating electric current is lower than 1.25><10"4A/cm2. The test of total corrosion finds that the corrosion-resistant performance of stainless steel layer is close to or superior to lCrl8Ni9;The ceramic layer has very high corrosion-resistant performance because it doesn't contain any FeAl2O4 which is easy to be corroded.