Effect of Chlorine and Sulphur on Stainless Steel (AISI 310) Due To High Temperature Corrosion

摘要

In a power station boiler, there are temperature of reg imes of corrosion which occurs mainly in the economizer, boiler steam generation tubes, super-heater tubes and air tubes. The specific gas temperatures in degrees centigrade for the following include: 150 – 370 o C for the economizer, 1000 – 1650 o C for the boiler steam generation tubes, 650 – 1000 o C for super-heater tubes and 1000 – 1200 o C for air tubes. For power station boilers that burn coal as the source of fuel it is recommended that a coal with low Chlorine and low Sulphur content is utilized to avoid the high rate of corrosion on the mentioned parts of the power station boiler. The major type of corrosion experienced by such power station boilers is called high temperature corrosion. For high temperature corrosion due to Sulphur, research has revealed that it can be reduced by ensuring that there is an oxidizing atmosphere and eluding flame impingement on the furnace walls that use "air belting" in the furnace basket. For high temperature corrosion due to chlorine, research has shown t hat chlorine attack starts at 204 o C while hydrogen chloride attack will occur until a temperature of about 426 o C. A suitable material that is suggested to be used in power station boilers, that has a high resistance corrosion rate is Stainless steel (AISI 310); substantial research has shown that it can be utilized in super-heater tubes.