AISI 4340 Steel
AISI 4340 Steel is a nickel chromium molybdenum alloy steel that widely used in Oil & Gas industry. It is a quality high tensile alloy steel. 4340 steel offers toughness and high strength in the heat treated condition. AISI 4340 is usually supplied under quenched and tempered condition at the hardness of 24 – 29HRc.
C: 0.38-0.43; Si: 0.15-0.35; Mn: 0.60-0.80; P: max0.035; S: max0.040;
Cr: 0.70-0.90; Mo: 0.20-0.30; Ni: 1.65-2.00;
Form of AISI 4340
Round / Square / Flat Bars, Shafts, Rollers, Blocks
Size of 4340 Steel
– As Forged
(Forged Flat Bars, Shafts, Rollers and Blocks can be Customized)
– As Rolled
Length: 3,000-10,000mm(can be Customized)
Tolerance on Dimension
– Black surface
Forged sizes up to 500mm (-0/+5mm)
Forged sizes above 500mm in diameter (-0/+8mm)
– Machined surface to all sizes (-0/+3mm)
Surface Condition of AISI 4340 Steel
If the bars are to be delivered with machined surface,the material shall be free of decarburized layer,black spots and cracks or other defects.
Quenched and Tempered (+QT) of SAE 4340 Steel
1. Heat 4340 steel slowly to 830-865°C;
2. Soak at this temperature then quench in oil;
3. Temper as soon as AISI 4340 reach room temperature (20°C);
4. Heat the steel carefully to a suitable temperature selected by reference to a tempering chart or table;
5. Soak at the temperature for 2 hours per 25mm of section;
6. Allow to cool in air.
Annealing of AISI 4340 Alloy Steel
1. Heat this material slowly to 800-860°C and allow enough time for it to be thoroughly heated.
2. Cool slowly in the furnace.
Other Technical Specification
1. Melting Process: EAF/BOF+LF+VD resulting in ingots
2. Both ends cut by saw
3. Ratio of forging:minimum 3:1
4. Grain size of final product: according to ASTM E112 more than 5,preferred more than 8
5. Ultrasonic test: As per SEP1921 Class C/c or D/d
According to EN10204 3.1,with mechanical properties (Tensile strength, Yield point, Elongation after fracture, Percentage reduction of area after fracture, Impact energy) and Hardness.
Enquiry for AISI 4340 Alloy Steel Round / Square / Flat Bars, Shafts, Rollers, Blocks.