Corrosion resistant alloys, also known as stainless steels or high performance alloys, are metallurgic compositions that offer enhanced corrosion resistance and mechanical properties compared to other materials. Corrosion resistant alloys are widely used in a variety of industrial applications, especially those exposed to corrosive environments or mechanical shock. seawater, oil and gas, chemical, and food processing industries due to their exceptional resistance to corrosion.
Corrosion resistant alloys are designated according to various national and international standards. The Chinese standard for corrosion resistant alloys in China is GB/T15007-1994. This standard defines the chemical composition, mechanical properties, production method, and structural performance of corrosion resistant alloys. According to the standard, corrosion resistant alloys are identified as three categories--austenitic, ferritic and martensitic steels.
Austenitic steels, also known as 300 series stainless steel, are the most popular and widely used corrosion resistant alloys in the industry due to their excellent resistance to corrosion and oxidation. This series of alloys contains about 18% chromium and 8% nickel, which gives them their superior corrosion resistance. In addition, they can withstand extreme temperatures up to 2000°F. However, they are also susceptible to stress corrosion cracking.
Ferritic stainless steel, also known as 400 series stainless steel, also contain chromium, but have a lower corrosion resistance than the 300 series. These alloys are used in industrial applications that require good mechanical strength but require less corrosion resistance than austenitic stainless steels. Typical applications include automotive exhaust systems and heat exchangers.
Martensitic steel, or 500 series stainless steel, contains a higher amount of carbon and chromium than the previous two series. These alloys are highly corrosion resistant, but can be easily machined and hardened. Martensitic stainless steel is often used to make knives, measuring tools, and valve components.
In summary, corrosion resistant alloys are essential for a wide range of industrial applications. These alloys are divided into three categories--austenitic, ferritic, and martensitic steels--which offer various levels of corrosion resistance and mechanical properties. The Chinese standard for corrosion resistant alloys in China is GB/T15007-1994.
