Study On The Non-toxic Substitution Of Anti Scale Explosion Reagent For Enamel Steel Based On EN10209 European Standard

Enamel products are made of high-quality steel plate and inorganic non-metallic materials with special functions after coating and sintering at high temperature,thus forming a strong chemical bond between the inorganic coating and the high-quality steel plate.Enamel products are not only beautiful in appearance,easy to clean,but also have the advantages of corrosion resistance and high temperature resistance,so they are widely used in daily life,medical equipment,engineering applications and other fields.Although enamel products are widely used,there are still some defects,such as pinholes,hemp bubbles,scale explosion and so on.Because of the irregular and irregular scale explosion,it is very important to detect the scale explosion resistance of enamel steel in advance.At present,there are three standards for testing the scale explosion resistance of enamel steel,which are international standard ISO17081:2014,European standard EN10209:2013 and Chinese national standard GB/T29515:2013.Among the three standards,international standards and Chinese national standards have higher requirements on the surface quality of steel plates,so the accuracy of detection is often limited.Compared with international standards and Chinese national standards,European standards have higher detection stability and accuracy.However,the detection solutions used in European standards are highly toxic reagents(HgCl₂ and As₂O₃),so the promotion of European standards as the standard for scale explosion resistance of enamel steel is limited.The scale explosion resistance of enamel steel is closely related to the type and quantity of precipitates in the steel plate.The results show that the larger the binding energy E_b between hydrogen atom and precipitates,the more beneficial the scale explosion resistance of the steel plate is.However,the relationship between the potential difference in the micro area of precipitates and the scale explosion resistance of enamel steel is rarely studied.In this paper,an evaluation method of scale explosion resistance of new enamel steel based on European standard en10209:2013 is studied,which is used to replace toxic reagents(HgCl₂and As₂O₃)in European standard.In addition,the relationship between the micro potential difference of different precipitates and the scale explosion resistance of enamel steel was studied,which provided a new direction for testing the scale explosion resistance of enamel steel.The conclusions are as follows:(1)By setting four concentration gradients,the stability of Na₂S 9(H₂O)as a substitute reagent in the same month was explored.The root mean square(RMS)of th in the four concentration tests of European standard and a,B,C and D were 4.05,4.95,5.48,4.24 and 4.60,and the standard deviations were 0.07,0.67,0.91,0.52 and 0.90,respectively.Therefore,the concentration of Na2S 9(H2O)as additive is 0.75 ml and the concentration is C.(2)The stability of the new solution in the thickness range of the European standard was verified.The experimental results showed that 0.75 ml of C concentration Na₂S 9(H₂O)as a substitute for As₂O₃ and HgCl₂,the applicable thickness range was 0.5?3 mm.(3)The stability and universality of Na₂S9(H₂O)as a substitute reagent were verified by comparing the scale explosion resistance of different types of enamel steel.According to the validity of the data,the critical threshold value of scale explosion test of new solution is 8.3.(4)The results show that the potential difference between the precipitates and the matrix is different.The precipitation phase of No.1 sample is Mn S,and the potential difference between the precipitate and the matrix is 245.68 mV.The TH value of the sample is 37.01?37.57.Ti(C,N)is the main precipitate phase in No.2 sample,which accounts for 74%of the precipitated phase.The potential difference between the precipitate and the matrix is 97.16 mV.The scale explosion resistance of the sample is 20.19?21.86.The number of precipitates per unit volume in No.1 sample is 0.035×10¹⁸ m^-3,and that in No.2 sample is 0.071×10¹⁸ m^-3.The number of precipitates in unit volume in sample 2 is more than that in sample 1.Therefore,Mn S is more beneficial to improve the scale explosion resistance of enamel steel.