Stainless Steel 440B is a high-carbon martensitic stainless steel known for its excellent corrosion resistance, hardness, and wear resistance. Its chemical composition typically includes around 0.75-0.95% carbon, 1.00% manganese, 1.00% silicon, 17.00-19.00% chromium, and small amounts of other elements like molybdenum and vanadium. This composition contributes to its exceptional hardness and abrasion resistance, making it suitable for various applications.
440B stainless steel is commonly used in the manufacturing of precision instruments, surgical equipment, and high-quality knives and blades. Its high carbon content allows for excellent edge retention and sharpness, making it a popular choice among knife makers.
Heat treatment plays a vital role in optimizing the properties of 440B stainless steel. It is typically hardened through quenching and tempering processes to achieve the desired balance of hardness and toughness. The steel should be heated to around 1010-1100°C (1850-2010°F) for the quenching process, followed by tempering at lower temperatures to reduce brittleness.
Machining 440B stainless steel can be challenging due to its high hardness and abrasion resistance. It requires slow speeds, rigid tooling, and appropriate cutting fluids to achieve precision machining results.
In terms of heat resistance, 440B stainless steel is not as heat-resistant as austenitic stainless steels but performs well in typical operating temperatures. It can withstand moderate heat without significant loss of structural integrity.
Corrosion resistance is a notable feature of 440B stainless steel. Its high chromium content forms a protective oxide layer on the surface, which helps resist corrosion, especially in mildly corrosive environments. However, it may not be as corrosion-resistant as some other stainless steel grades, like 316 or 304, in highly corrosive conditions.
|440B (1.4112)||%0.85-0.95||%1.0 max||%0.040 max||%0.03 max||%1.00 max||
||Yield Strength 0.2% (MPa)||Ultimate Tensile Strength (MPa)||Elongation 2″%||Reduction of Area||Brinell Hardness|
|Alloy 440B||Hardened 1900°F, oil quench, tempered 600°F||1655||1793||5||20||512|