Alloy Pipe – From Elements To Applications

Chromium (Cr)

Its primary function is to enhance corrosion resistance and high-temperature resistance. When the chromium content exceeds 10.5%, a passive film of Cr₂O₃ forms on the pipe surface, isolating it from the outside world and achieving corrosion protection. This stable passive film also makes the pipe more resistant to high temperatures and improves strength.

Nickel (Ni)

Nickel forms a stable austenite and is the primary element in austenite. It significantly enhances toughness and corrosion resistance at low temperatures, making it easier to form during processing.

Molybdenum (Mo)

Molybdenum can be added to stainless steel in the presence of chlorides, such as seawater or chloride ion solutions, to improve its corrosion resistance. The addition of molybdenum also increases the hardenability during heat treatment, resulting in a more uniform overall material. Molybdenum also increases the recrystallization temperature, significantly improving high-temperature resistance and creep resistance.

Manganese (Mn)

Manganese, like molybdenum, has the same properties as molybdenum: it improves hardenability during heat treatment and achieves a more uniform overall material. Manganese can also be used as a deoxidizer and desulfurizer. Dissolving in ferrite, it increases the strength of steel. Manganese is also present in austenite.

Silicon (Si)

Silicon’s primary use is as a deoxidizer. Silicon is much more effective than manganese as a deoxidizer, improving the pipe’s oxidation resistance, strength, and hardness.