Effects of the Solid Solution Heat Treatment on the Corrosion Resistance Property of SSC13 Cast Alloy

Abstract

Recently, Stainless steels have been increasingly selected as the fitting or the valve materials of water pipes as the human health issue is getting higher and higher. Therefore, the connectors attached at pipes to deliver water are exposed to more severe environments than the pipes because crevice or galvanic corrosion is apt to occur at the fittings or the valves. Effects of the solid solution annealing, cooling rate after this heat treatment, and passivation on the corrosion properties of the shell mold casted SSC13 (STS304 alloy equivalent) were studied. The heating and quenching treatment more or less reduced hardness but effectively improved corrosion resistance. It was explained by the reduction of delta ferrite contents. Independent of heat treatment, the chemical passivation treatment also lowered corrosion rate but the improvement of corrosion resistance depended on temperature and time for passivation treatment indicating that the optimum conditions for passivation treatment were the bath temperature of 34 o C and operating time of 10 minutes. Therefore it is suggested that the corrosion resistance of SSC13 can be effectively improved with the heat treatment, where SSC13 is heated for 10 minutes at 1120 °C and quenched and passivation treatment, where SSC13 is passivated for at least 10 seconds at 34 °C nitric acid solution.

The Effect of Solution Annealing on the Property of Passivated Surface in CF8 Stainless Steel

“…This indicates the formation of enhanced film protection. The resistance to corrosion increased by more than a factor of two when the solution annealing and chemical passivation were applied [23]. Figure 2 shows surface roughness of the different specimen.…”

Effect of Solution Annealing on Alpha Prime Martensitic Microstructure of Cold Rolled AISI316L Stainless Steel

“…The martensitic transformation is expected to change by stress states. Even though stainless steels are known having a good resistance to general corrosion because they form a thin chromium rich passive surface film, they are susceptible to localized corrosion attack such as pitting, intergranular corrosion, and stress corrosion cracking [12][13][14][15][16][17]. We study the effects of solution annealing and load reversals on α' martensitic phase of cold rolled AISI316L.…”