What is the difference between Monel alloy and stainless steel?
Monel 400 alloy (UNS N04400 or MCu-28-1.5-1.8 or Ni68Cu28Fe) is a nickel-based alloy material. It has excellent corrosion resistance in seawater, chemical solvents, ammonia sulfur chloride, hydrogen chloride, and acidic media such as sulfuric acid, hydrofluoric acid, hydrochloric acid, phosphoric acid, and organic acids, as well as alkaline media, salts, and molten salts. In addition, it has excellent mechanical properties, can be used in a wide range from low temperature to high temperature, and has good welding performance and medium to high strength.
Monel400 alloy is a solid solution strengthened alloy. Its alloy grade is UNS N04400, named according to the "ASTM-SAE Unified Number System". Compared with the common austenitic stainless steel 1Cr18Ni9Ti, Monel400 alloy has differences in physical and mechanical properties. The alloy has excellent electrical and thermal conductivity, its resistivity is about 70% of 1Cr18Ni9Ti, and its thermal conductivity is 36% higher than 1Cr18Ni9Ti.
Monel400 has good welding performance and can be used with arc welding (SMAW), argon arc welding (GTAW), inert gas shielded welding (GMAW) and other welding methods. Similar to austenitic stainless steel, no preheat treatment is required before welding, and no heat treatment is required after welding. Its welded joint form is similar to austenitic stainless steel, but it also has its own unique features.
Monel400 has good welding performance and can be used with arc welding (SMAW), argon arc welding (GTAW), inert gas shielded welding (GMAW) and other welding methods. Similar to austenitic stainless steel, no preheat treatment is required before welding, and no heat treatment is required after welding. Its welded joint form is similar to austenitic stainless steel, but it also has its own unique features.
The first is the difference in chemical composition: Monel is a nickel-based alloy, usually based on nickel, generally containing about 60% nickel, and copper and other elements are added as needed; stainless steel is an iron-based alloy, generally containing chromium An iron-based alloy with more than 12.5% can be called stainless steel. Depending on the grade of stainless steel, elements such as nickel, platinum, and potassium will be added.
Secondly, the materials have different adaptability to the environment in which they are used. Generally, stainless steel is suitable for oxidizing environments, but is not suitable for environments containing high chloride ions, especially environments containing fluorine. Monel alloys can be used in reducing environments, such as those containing It is more suitable to use fluorine environment, but stainless steel cannot be used.
