Stainless steel is a popular material used in various applications due to its excellent corrosion resistance properties. However, it is still susceptible to intergranular corrosion (IGC) under certain conditions. IGC is a form of corrosion that occurs along the grain boundaries of stainless steel, which can result in a loss of mechanical strength and premature failure.

To evaluate the susceptibility of stainless steel to intergranular corrosion, various test methods have been developed. One of the most common methods used to test for IGC is the intergranular corrosion test (IGC test). The IGC test is a laboratory test that is used to determine the resistance of stainless steel to IGC.

The IGC test involves immersing a sample of stainless steel in a solution containing a specific mixture of chemicals at a predetermined temperature for a specific time period. The solution typically contains a strong oxidizing agent, such as nitric acid, which reacts with the chromium at the grain boundaries and causes the steel to corrode selectively along the grain boundaries. The severity of the corrosion is evaluated by examining the surface of the sample and measuring the depth of the corrosion pits.

There are several different methods for conducting the IGC test, including the Huey test, Strauss test, and the G28 test. Each method uses a slightly different set of conditions, such as temperature, chemical composition, and duration of the test, to evaluate the susceptibility of the stainless steel to intergranular corrosion.

Overall, the IGC test is an important tool for evaluating the corrosion resistance properties of stainless steel and ensuring that it is suitable for use in various applications where corrosion resistance is critical.