Potassium hydroxide, also known as caustic soda, is an important industrial product with a wide range of uses. It is a kind of strong alkali, and its corrosion is not serious at room temperature, but it will seriously corrode many metals at high temperature and stress. Steel can be used in dilute sodium hydroxide solution at room temperature, but it will corrode rapidly with the increase of temperature or concentration. It is important to study the corrosion of different alloys in sodium hydroxide solution for material selection.

　　氫氧化鉀材料選擇的依據：常溫下不具有腐蝕性，但在高溫和應力下會對很多金屬造成嚴重腐蝕。不同溫度下不同濃度氫氧化鈉溶液的設備和管道選材不一，氫氧化鈉溶液的濃度為0 ~ 30%。如果溫度低于50℃，用一類材料制造的設備和管道通常耐腐蝕；而0% ~ 30%的氫氧化鈉溶液在50 ~ 100℃時對二類材料制成的設備和管道有較好的耐腐蝕性。

　　The selection basis of potassium hydroxide material: it is not corrosive at room temperature, but it will cause serious corrosion to many metals at high temperature and stress. The material selection of equipment and pipelines with different concentrations of sodium hydroxide solution at different temperatures is different, and the concentration of sodium hydroxide solution is 0 ~ 30%. If the temperature is lower than 50 ℃, the equipment and pipes made of first-class materials are usually corrosion-resistant; while 0% - 30% sodium hydroxide solution has good corrosion resistance to the equipment and pipes made of second-class materials at 50-100 ℃.
             

　　針對氫氧化鈉具有良好的耐腐蝕性，其次是鎳。銀和鎳可以承受所有濃度和溫度的氫氧化鈉，直到熔融狀態(480℃)。適用于高溫、高濃度的堿、鎳及其合金(如鉻鎳鐵合金、蒙乃爾合金等。)是首要選擇。不銹鋼對40% ~ 50%以下的NaOH溶液能耐受80 ~ 100℃，但不能耐受高濃度高溫堿液。碳鋼在低溫稀NaOH溶液中具有良好的耐腐蝕性，能在表面形成固態氧化保護膜。由于價格低廉，往往是很多用戶的首要選擇。

　　Sodium hydroxide has good corrosion resistance, followed by nickel. Silver and nickel can withstand all concentrations and temperatures of sodium hydroxide until the molten state (480 ℃). It is suitable for high temperature and high concentration alkali, nickel and its alloys (such as Cr Ni Fe alloy, Monel alloy, etc.). ）It's the first choice. Stainless steel can withstand 80-100 ℃ for NaOH solution below 40% - 50%, but it can't tolerate high concentration of high temperature alkali. Carbon steel has good corrosion resistance in low temperature dilute NaOH solution, and can form solid oxidation protective film on the surface. Because of the low price, it is often the first choice for many users.