300M Alloy - Vacuum Melted Silicon-Vanadium Steel Alloy

300M is a low alloy, vacuum melted, steel of very high strength. Essentially it is a modified AISI 4340 steel with silicon, vanadium and slightly more carbon and molybdenum. 300M has a very good combination of strength at 1930–2100 MPa (280-305 ksi), toughness, fatigue strength and good ductility. It is a through hardening alloy.

300M Alloy Industry Standard

300M alloy complies with the AMS 6419 industry standard and is also known as UNS K44220.

Applications of the 300M Alloy

The 300M alloy is use for a wide range of applications including:

• aircraft landing gear
• high strength bolts
• airframe parts
• driveshafts

Heat Treatment of 300M Alloy

300M must be normalized at 927°C (1700°F) before hardening. After the normalizing treatment, the alloy is hardened by heating to 871°C (1600°F) and oil quenching. After hardening the material is double tempered for 2 hours at 302°C (575°F) and 2 hours at 302°C (575°F) air cool.

Chemical Composition of 300M Alloy

The Super Alloys ultra-high strength 300M alloy has the following chemical composition that gives it its unique properties.

Table 1. Chemical composition of 300M alloy

Mechanical Properties of 300M Alloy

The mechanical properties of 300M alloy following different heat treatments are outlined in the following tables.

Table 2. Mechanical properties for normalized, hardened and double tempered

Physical Properties of 300M Alloy

The physical properties of 300M alloy are outlined in the following table.

Table 3. Physical properties of 300M alloy

Available Product Forms of 300M Alloy

300M alloy is available in the forms of plate, bar, sheet, tube, billet, and forging

This information has been sourced, reviewed and adapted from materials provided by NeoNickel.

For more information on this source, please visit NeoNickel.