Induction hardening is a form of heat treatment in which a metal part is heated by induction heating and then quenched. The quenched metal undergoes a martensitic transformation, increasing the hardness and brittleness of the part. Induction hardening is used to selectively harden areas of a part or assembly without affecting the properties of the part as a whole. The hardening depth is 1.5-5mm; medium/low-frequency quenching may lead to excessive depth and negative effect on strength; high-frequency quenching generally result in a shallow depth, and may ensure the balance of hardness and strength.
AISI SAE 4140 alloy steel is a chromium molybdenum alloy steel specification widely used in general purpose high tensile steel for components, like cylinder rod, shafts, bolts, gears and other applications.
Common 4140 Steel Specifications
|Standard||ASTM A29||DIN 17200||BS 970||JIS G4105||GB/T 3077||AS 1444|
3. 4140 Steel Bar Chemical Composition