Grade Introduction:

SAE 8620 Alloy Steel is a low alloy nickel, chromium, molybdenum case hardening steel, generally supplied in the as-rolled condition with a maximum hardness HB 255max. SAE 8620 alloy steel offers high external strength and good internal strength, making it highly wear-resistant. SAE 8620 steel has a higher core strength than grades 8615 and 8617. SAE 8620 alloy steel is flexible during hardening treatments, thus enabling improvement of case/core properties. Prehardened and tempered (uncarbonized) 8620 can be further surface hardened by nitriding but will not respond satisfactorily to flame or induction hardening due to its low carbon content. SAE 8620 alloy steel is suited for applications that require a combination of toughness and wear resistance. This grade is commonly supplied in a round bar.

Grade Application:

The SAE 8620 can be used for a number of medium-strength applications such as camshafts, fasteners, gears, and chains/chain pins.

Equivalent grades:

Chemical composition:

The following table shows the chemical composition of SAE8620 steel:

Hardening:

149

Heat Treatment :

This alloy may be hardened by heating to 1500 F followed by a water quench. Carburize at 1650 to 1700 F in an appropriate carburizing medium and oil quench to harden. Improved carburized case and core properties can be obtained by furnace cooling from carburizing at 1650 – 1700 F and then reheating to 1575 F.