Corrosion and Materials

Graphitization is a change in the microstructure of certain carbon steels and 0.5 Mo steels after long term operation in the 800º F to 1100º F range. During this process, carbon precipitates from the steel matrix as graphite, leading to a reduction in the toughness and strength of the steel.

304 stainless steel is classified as an austenitic stainless steel. This category is known for its excellent corrosion resistance and weldability, largely due to its high chromium and nickel content. Austenitic stainless steels are also non-magnetic and cannot be hardened by heat treatment. Common applications of 304 stainless steel include kitchen equipment, chemical processing equipment, and food processing machinery.

Thermal fatigue is the phenomenon that occurs due to cyclic stress caused by variations in temperature. It typically results from repeated thermal cycling, which can cause materials to crack or fail over time as they expand and contract with temperature changes.

Cooling water corrosion refers to the general or localized corrosion of carbon steels and other metals caused by dissolved salts, gases, organic compounds, or microbiological activities in cooling water systems. This type of corrosion is specifically related to conditions found in cooling water environments, making it the most suitable answer for the question.

410 stainless steel is categorized as martensitic. Martensitic stainless steels are known for their high strength and hardness, along with moderate corrosion resistance. They typically have higher carbon content and can be heat treated to provide a range of mechanical properties. Types 410, 416, 420, 440A, 440B, and 440C are indeed part of the martensitic family.