4340 steel is a nickel-chromium-molybdenum alloy steel. It will gain high strength after being heat treated. It also has good toughness, fatigue resistance, impact toughness, and other properties. Its equivalent grades are JIS SNCM439 and DIN 1.6511 / DIN 1.6582. The properties and composition of 4340 steel round bar sheet plate are as follows.

It is an alloy structural grade used by SAE International(SAE), and it is chrome-nickel low-alloy steel. 4340 steel round bar sheet plate will get high tensile strength, hardness and toughness after heat treatment.

It is used widely in the transmission components of heavy chemical machinery. Different sections of each part of the casting which cause the temperature difference stress and phase transformation stress. If you can’t understand their laws and characteristics, you can’t use rational processes.

The consequence is that there is a risk of cracking the casting during the casting or heat treatment. So the control of chemical composition and the choice of the heat treatment process for the casting are really important.

1.6511 Steel Application
4340 alloy steel is used to manufacture large and medium-sized plastic molds that require high strength and toughness. And it is used for making important quality controlling parts with good toughness, high strength, and large size, such as heavy machinery and high load shafts, dia of turbine shafts is larger than 250mm, helicopter rotor shafts, turbojet turbine shafts, blades, high-load transmission parts, crankshaft fasteners, gears and etc.

After nitriding, it also can be used to make important parts for special performance requirements. And it will be a great material for high strength and good plasticity parts after low-temperature tempering or isothermal quenching.

1. 6511 Steel Characteristics
1. It has great atmospheric corrosion resistance, fatigue resistance and strength.
2. Stay excellent toughness, wear resistance and fatigue strength after heat treated.
3. It is alloy steel with low carbon and high nickel. About the coating and softening for leather knife sheath, it is a great choice.
4.4340 alloy steel bar is used widely in the aerospace industry because of great strength.

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