Analysis of defects caused by heat treatment of crusher jaw plate using medium frequency induction heating power supply

Jaw crusher is a crushing machine widely used in power generation, mining, building materials and other industries. It is required to have high hardness, wear resistance and service life in the working process, and the jaw plate is the main wearing part. Therefore, many production Manufacturers use medium frequency induction heating power supply for quenching heat treatment to improve its service life. However, in the process of operation, affected by many factors such as the environment, workpiece raw materials, heat treatment process, etc., the jaw plate may have various defects during the heat treatment process. Today, the editor will analyze and analyze the defects and their countermeasures for you.

1. Wear and tear

The cause of wear may be mixed materials or low carbon content. Therefore, we should strictly check the raw materials to ensure that the raw material composition meets the requirements.

2. Carbide precipitation

1) The heating time is insufficient or the temperature is low, and the carbides are not all dissolved in the austenite. We should implement reasonable heat treatment heating temperatures and holding times to ensure full dissolution of carbides.

2) Improper cooling leads to carbide precipitation. We should control the cooling water temperature strictly in accordance with the process requirements.

3. Cracks

1) It is a heat treatment crack, with low thermal conductivity, and the thermal expansion coefficient is twice that of carbon steel. The water toughening treatment does not have a good temperature rise rate, and the time of furnace and water entry is improper, and carbides are precipitated on the grain boundary. Therefore, we strictly and reasonably control the heating rate and the water cooling time. The time from opening the furnace door to the workpiece entering the water should be controlled within 2 minutes to avoid the water temperature being higher than 20°C.

2) Cracks generated during the working process are caused by internal casting defects. Under the action of impact load, cracks sprout around shrinkage holes and loose parts, and cracks are formed after fatigue expansion.

It can be seen from the above description that the main reasons for the defects of the workpiece during the heat treatment process are that the composition of the raw materials does not meet the requirements, and the heat treatment process is not properly operated. Therefore, strengthening the quality inspection of workpiece raw materials and improving the heat treatment process are effective ways to avoid defects.