Overview
Product Details
APPLICATIONS: AISI4340 is a nickel-chromium-molybdenum alloy steel known for its toughness and its ability to attain high strengths in the heat-treated condition. It has very good fatigue resistance. This alloy, 4340, may be heat treated to high strength levels while maintaining good toughness, wear resistance and fatigue strength levels, combined with good atmospheric corrosion resistance, and strength up to around 600 º F (315 º C.) . Commercial and military aircraft, automotive systems, forged hydraulic and other machine tool applications, forged steel crankshafts. Chemical composition: AISI 4340 C Si Mn P S Cr Mo Ni min. 0.38 0.15 0.60 0.70 0.20 1.65 max. 0.43 0.30 0.80 0.035 0.040 0.90 0.30 2.00 MACHINABILITY This grade is readily machinable, with either a coarse lamellar pearlitic structure or a spheroidized structure being best advised, depending upon section size and complexity and amount of machining to be carried out. If there is doubt about the suitability of any other structure, then a spheroidizrd structure should be aimed for in heat treatment. WELDABILITY This grade is readily welded in the annealed condition, but welding in the hardened and tempered condition should be avoided where possible because of the effect on mechanical properties. Welding in the nitrided or flame or induction hardened conditions is not recommended. Production: Round and Flat Size according to customer's requirement.