What is the process of Martempering?

What is the process of Martempering?

Martempering is also known as stepped quenching or interrupted quenching. In this process, steel is heated above the upper critical point (above the transformation range) and then quenched in a salt, oil, or lead bath kept at a temperature of 150-300 °C.

What is austempering and Martempering?

Austempered products are heated at an even higher level than martempered ones, typically between 840 and 950 degrees Celsius. This not only produces a uniform interior and exterior temperature, but allows the bainite microstructure to form throughout the product. It can be used with ductile iron or steel workpieces.

What are the advantages of Martempering over conventional hardening?

The primary advantage of martempering is that parts will have lower distortion and reduced residual stress. This is from reduced thermal gradients during quenching and relatively uniform transformation of martensite. Martempering can be accomplished in either oil or molten salt.

What is austempering heat treatment?

Austempering is a heat treating process for medium-to-high carbon ferrous metals which produces a metallurgical structure called bainite. It is used to increase strength, toughness, and reduce distortion.

What is Marquenching?

Marquenching/Martempering is a form of heat treatment applied as an interrupted quench of steels typically in a molten salt bath at a temperature right above the martensite start temperature. The purpose is to delay the cooling for a length of time to equalise the temperature throughout the piece.

What is meant by Martempering?

Definition of martempering : the process of quenching steel from above the transformation temperature in a bath at about 350° F and then cooling to room temperature after the temperature has become nearly uniform with the bath.

What is meant by martempering?

What are the advantages of Martempering?

The reported advantages of martempering include less distortion, elimination of quench cracking, improved fatigue resistance, and improved absorbed impact energy. Data regarding improved impact energy are sparse and appear to be most widely reported for the high-carbon steels.

Is austempering a tempering process?

The key difference between tempering and austempering is that tempering is useful in removing the excessive hardness of steel, whereas austempering is important in reducing the distortion of iron alloys.

What is the purpose of Martempering?

What is the process of Normalising?

Normalising involves heating a material to an elevated temperature and then allowing it to cool back to room temperature by exposing it to room temperature air after it is heated. This heating and slow cooling alters the microstructure of the metal which in turn reduces its hardness and increases its ductility.

What do you mean by Martempering?

What is the meaning of martempering?

Definition of martempering. : the process of quenching steel from above the transformation temperature in a bath at about 350° F and then cooling to room temperature after the temperature has become nearly uniform with the bath.

What is marquenching and why is it used?

Since marquenching lowers the residual thermal stress, it is used for parts with complex geometries, diverse weights, and section changes. Marquenching is used primarily to minimise distortion and eliminate cracking. Alloy steels are generally more adaptable to marquenching.

How are marquenched parts tempered?

Marquenched parts are tempered in the same manner as conventional quenched parts. Steel is marquenched and tempered by: Quenching from the austenitising temperature into a hot fluid medium at a temperature usually above the martensitic range; Holding in the quenching medium until the temperature throughout the steel is substantially uniform;

What is the advantage of martempering over quenching?

The advantage of martempering is the reduction of thermal stresses compared to normal quenching. This prevents cracking and minimises distortion. Martempering is used to produce martensite without developing the high stresses that usually accompany its formation. It is similar to conventional hardening except that distortion is minimized.