Will Stainless Steel Casting Parts be damaged due to long-term exposure to harsh environments?

Stainless steel casting parts may indeed be damaged when exposed to harsh environments (such as high temperature, strong corrosion, extreme weather, etc.) for a long time. Although stainless steel itself has strong corrosion resistance and high temperature resistance, its durability is still affected by many factors. The following are some factors and mechanisms that may cause damage to stainless steel casting parts:

1. The influence of corrosive environment
Chloride corrosion: If stainless steel casting parts are exposed to chlorine-containing environments (such as oceans, chemical plants, etc.) for a long time, chlorides will promote stress corrosion cracking (SCC). Even for stainless steel, some types (such as 304 stainless steel) are prone to corrosion in such environments, especially when stress exists.
Acid and alkali corrosion: In strong acid or alkali environments, especially when exposed for a long time, localized corrosion (such as pitting and crevice corrosion) may affect the integrity of stainless steel castings. Chemical reactions at high temperatures may also cause the corrosion rate to accelerate.
Oxidation corrosion: In high temperature environments (such as boilers, gas turbines, etc.), the surface of stainless steel may oxidize, resulting in the formation of an oxide layer, which affects the surface quality and durability. Especially when exposed to air at high temperatures, the oxidation process is intensified, which may cause the surface to become rough, discolored or lose its luster.
2. Effects of high temperatures
Creep: Stainless steel may creep in high temperature environments, especially when it exceeds the service limit temperature of stainless steel (usually 800°C to 1000°C). Creep is the process by which a metal gradually undergoes plastic deformation under long-term exposure to high temperatures and stress. This deformation causes deformation of the casting, stress concentration, and may cause fatigue cracking.
Thermal fatigue: Thermal fatigue may occur if stainless steel casting parts experience frequent high temperature changes (such as rapid cooling from high temperature to low temperature). Such repeated temperature changes can cause microcracks in the metal, which may eventually cause the casting to crack or fail.
Thermal cracking: During the casting process, if the cooling rate is uneven or too fast, it may cause the formation of thermal cracks. These cracks will gradually expand and affect the structural integrity of the part when exposed to high temperatures for a long time.
3. Mechanical stress and fatigue
Stress corrosion cracking (SCC): As mentioned earlier, stainless steel castings may experience stress corrosion cracking when exposed to stress and corrosive environments for a long time. Even stainless steel with strong corrosion resistance may crack under the combined action of high temperature and chemical media when subjected to external mechanical loads or internal stresses for a long time.
Fatigue damage: Long-term mechanical loads, especially cyclic loads or alternating loads, can lead to the appearance of fatigue cracks. Although stainless steel has good fatigue resistance, high-intensity long-term alternating loads (such as applications in the automotive and aviation fields) may still cause cracks to develop and eventually cause rupture.
4. Surface damage and wear

Mechanical wear: In high-friction and high-pressure environments, the surface of stainless steel castings may suffer from wear, especially those castings used in moving parts (such as pump bodies, valves, etc.). Long-term friction can cause surface fatigue and loss of metal materials, thereby weakening the structural strength of the parts.
Impact and collision: If stainless steel castings are exposed to environments with large impact or collision, they may crack or surface depression, especially under low temperature or brittle conditions.
5. Pollutants in the environment
Pollution deposition: In some industrial environments, pollutants such as industrial smoke, acid mist, and salt mist may adhere to the surface of stainless steel. If they are not cleaned and treated for a long time, these pollutants may cause local corrosion, damage the surface, and affect its appearance and durability.
Sulfide and ammonia in the air: When these gases react with stainless steel, they may form a film on the surface, causing corrosion. Especially in industrial environments, long-term exposure to these gases will accelerate the corrosion process.
How to improve the durability of stainless steel casting parts in harsh environments?
Choose the right material: Different types of stainless steel alloys have different corrosion resistance. For example, 316 stainless steel has stronger resistance to chloride corrosion than 304 stainless steel; **duplex stainless steel** performs well in high temperature and corrosive environments and is suitable for special applications such as chemical and marine.
Surface treatment: Surface treatment of castings (such as electroplating, passivation, and spraying) can significantly improve their corrosion resistance and wear resistance, especially in chemical corrosion or high temperature environments. Passivation treatment can form a stable passivation film to reduce the occurrence of corrosion.
Heat treatment process: Through appropriate heat treatment processes, such as annealing and solution treatment, the corrosion resistance, strength and toughness of stainless steel can be improved, and the occurrence of cracks, thermal fatigue and other problems can be reduced.
Regular maintenance and inspection: Regularly check the surface condition of stainless steel castings, remove pollutants in time, clean and maintain them, avoid the accumulation of corrosive substances, and reduce corrosion and wear.
Prevent stress concentration: During the design and manufacturing process, ensure that the structure of the casting does not have excessive stress concentration, avoid excessive local stress, and thus reduce the risk of stress corrosion cracking.

Stainless steel casting parts may indeed be damaged when exposed to harsh environments for a long time, especially under the combined effects of high temperature, corrosive substances, mechanical stress and other factors. In order to improve its durability in this environment, the occurrence of damage can be reduced by selecting appropriate materials, surface treatment, heat treatment processes and regular maintenance to ensure the long-term reliability and performance stability of stainless steel castings.