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.
氢氧化钾材料选择的依据：常温下不具有腐蚀性，但在高温和应力下会对很多金属造成严重腐蚀。不同温度下不同浓度氢氧化钠溶液的设备和管道选材不一，氢氧化钠溶液的浓度为0 ~ 30%。如果温度低于50℃，用一类材料制造的设备和管道通常耐腐蚀；而0% ~ 30%的氢氧化钠溶液在50 ~ 100℃时对二类材料制成的设备和管道有较好的耐腐蚀性。
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 ℃.
针对氢氧化钠具有良好的耐腐蚀性，其次是镍。银和镍可以承受所有浓度和温度的氢氧化钠，直到熔融状态(480℃)。适用于高温、高浓度的碱、镍及其合金(如铬镍铁合金、蒙乃尔合金等。)是首要选择。不锈钢对40% ~ 50%以下的NaOH溶液能耐受80 ~ 100℃，但不能耐受高浓度高温碱液。碳钢在低温稀NaOH溶液中具有良好的耐腐蚀性，能在表面形成固态氧化保护膜。由于价格低廉，往往是很多用户的首要选择。
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.