Experimental Research On Stress Corrosion Cracking Of 304 And 316L Austenitic Stainless Steel In Dye Solution

The dyeing machine is the main pressure vessel of the printing and dyeing industry. Frequently, the vessel came about leak, cracking even explosion, due to the complex and corrosive dye solution, which always caused serious economical loss and human injury. As the ordinary material of petroleum chemical equipments, wide and in-depth researches have been carried out on the stress corrosion in austenitic stainless steel by many experts all over the world, and a great number of research results were reported. But, as the commonly material of the dyeing machine, there was little research on the stress corrosion in the environment of the dye solution. Therefore, there will be practical applications to research the stress corrosion of austenitic stainless steel in the dye solution environment, and Accumulate experimental data for the stress corrosion of austenitic stainless steel in the dye solution environment.The base metal and the heat affected zone of 304 and 316L austenitic stainless steels were chosen as the research objects in this paper, and the slow strain rate test (SSRT) and wedge opening loading (WOL) test were adopted to study the stress corrosion in the dye environment in the lab. Through these investigations, the sensitivity of SCC, the crack propagation rate and the critical stress intensity factor of stress corrosion of 304 and 316L austenitic stainless steels in dye solution environment are mastered.The main results of the researches are summarized as follows:1. The SSRT results of 304 austenitic stainless steel show that: at normal temperature, the SCC tendency of the base metal and the heat affected zone are very obviously in the dark solution; but, in the light solution, only the heat affected zone shows obvious SCC tendency.2. The SSRT results of 316L austenitic stainless steel show that: at normal temperature, whatever the solution is, the base metal doesn't show obvious SCC tendency; to the heat affected zone material, the SCC tendency in the dark dye solution is obvious, while there is no obvious SCC tendency in the light solution.3. The WOL test results of 304 austenitic stainless steel show below: under the dark dye solution environment, the SCC propagation rate of the base metal and the heat affected zone respectively are 9.46×10-8～9.76×10-8 and 7.51×10-8～16.2×10-8 , the critical stress intensity factor of stress corrosion (KISCC) respectively are 104.521mm/s mm/s mm/s mm/sMPa m and 107.085MPa m .4. The WOL test results of 316L austenitic stainless steel show below: under the dark dye solution environment, the SCC propagation rate of the base metal and the heat affected zone respectively are 6.62×10-8～8.04×10-8 and 6.21×10-8～12.9×10-8 , the critical stress intensity factor of stress corrosion (KISCC) respectively are 104.082mm/s mm/s mm/s mm/sMPa m and 105.601MPa m .5. The results of comparing the test data about the two materials show that: the SCC tendency and the SCC propagation rate of 304 austenitic stainless steel are both higher than that of 316L austenitic stainless steel; to the same material, the SCC tendency and the SCC propagation rate of the heat affected zone are both higher than that of the base metal.