Laborate Star

The Jominy End Quench apparatus is a standard laboratory setup used to determine the hardenability of steel, i.e., the ability of steel to harden in depth when quenched.

Main Components

1. Specimen Holder

   • Holds a standard cylindrical steel specimen (usually 25 mm diameter × 100 mm length) in a vertical position.

2. Water Jet Nozzle

   • Positioned directly below the lower end of the specimen.

   • Produces a controlled, steady jet of water that quenches only one end of the specimen.

3. Water Supply System

   • Includes a water tank, flow control valve, and piping to ensure a constant and specified water flow rate and temperature.

4. Base and Support Frame

   • Provides stability and correct alignment of the specimen and nozzle.

5. Heating Furnace (used with the apparatus)

   • The specimen is heated in a furnace to the austenitizing temperature before being transferred to the quenching setup.

Working Principle

• The heated steel specimen is mounted vertically in the apparatus.

• A jet of water impinges on the bottom end only, causing rapid cooling at that end.

• Cooling rate decreases gradually along the length of the specimen away from the quenched end.

• This produces different microstructures and hardness values along the length.

• After quenching, hardness is measured at fixed intervals from the quenched end to evaluate hardenability.

Purpose

• To compare hardenability of different steels.

• To select suitable steel for components of varying thickness.

• To study the effect of alloying elements on hardenability.