Optimization Of Properties Of The Glass Lined Piping

In this thesis,by means of the semi-empirical formula of enamel powder used for glass lined piping,we improved the expansion coefficient of the enamel layer to prevent the cracking accident between enamel layer and metal substrate caused by the temperature change.Meanwhile,we also optimized the melting point of formula for the acid resistance enamel powder,which had the good viscosity and fluidity at the temperature of about 900?and it could sufficiently infiltrate the metal substrate and release the gas produced from the metal substrate.In addition,in order to improve the alkali resistance of glass lined piping's enamel layer,we tried to increase the metallic oxides to improve its alkali resistance ability?titanium,stannum,zirconium oxide series?.As the weakness of alkali resistance of titanium series formula,which could not meet the requirements of corrosion resistance of 24hrs soaked in sodium hydroxide solution at 80?written in GB25025,this time we only estimated the formula of stannum and zirconium series.And after we added 6%-9%ZrO₂ in the formula,we found that the alkali resistance of enamel layer was greatly improved.Therefore,we decided to adopt ZrO₂series formula to enhance the alkali resistance ability for the glass lined pipings.During the experiment,the SPSS22.0 software was used to analyze the expansion coefficient and melting point of the 20 sets data of alkali resistant formula of stannum and zirconium system.We found that the linear expansion coefficient and melting point of the two sets obey the normal distribution.Furthermore,we used P-P charts to confirm that the cumulative probability curve of the two formulations can meet the normal distribution requirements.Finally,the box graphs were used to confirm that the composition of stannum series and zirconium series had certain similarity in the coefficient of expansion and melting point.We also used the MATLAB software to verify the clustering method to evaluate the differences of acid and alkali resistant abilities of stannum series and zirconium series formulas,and the results showed that the enamel layer made from zirconium series formula was better.Through the characteristics of chemical reaction of bottom glaze,surface glaze and metal substrate at different temperatures during the sintering stage,we adopted the method by sintering the products at a specific temperature point for a period of time.In addition,in the welding seam area,the basic welding rod which is difficult to release gas under high temperature was used to cover the surface,so as to prevent the bubbles occurring on the bottom glaze layer,which could result in the cracking accident on the enamel layer.