Reasons for insufficient hardness in induction heating quenching

Insufficient hardness is a common occurrence after induction hardening. There are two main reasons for insufficient hardness after induction heating quenching. One situation is that the hardness of the heated part is insufficient or there are soft spots, and the other situation is that the overall hardness of the quenched part is insufficient. When the above two situations of insufficient hardness occur, it is necessary to determine which specific situation it belongs to based on the actual situation, analyze the reasons based on the specific manifestations of insufficient hardness, and find solutions. 

Heating raw materials is one of the important reasons for insufficient hardness after induction heating quenching. Our company will analyze the reasons for insufficient hardness in the selection of heating raw materials and provide solutions. 

Selection of Heating Materials for Induction Heating Quenching 

In terms of the selection of heating materials, there are mainly two situations where the hardness is not sufficient after quenching. 

1. Improper heating of raw materials or selection of low-quality raw materials 

① Inappropriate heating of raw materials 

The workpiece that should have been made of alloy tool steel was replaced by a workpiece made of ordinary high carbon steel; 

Workpieces that should have been made of high carbon or medium carbon steel were instead made of low carbon steel. 

The incorrect selection of these two heating materials can result in insufficient hardness or soft spots in induction heating quenching. 

② Selected low-quality raw materials 

When selecting raw materials, inferior heating materials may be used due to price reasons, resulting in insufficient hardness or soft spots during quenching that do not meet the heating standards. 

2. Uneven microstructure of heated raw materials 

If there is separation or aggregation of fine structures in the heated raw materials, it can also lead to insufficient hardness and soft spots after induction heating quenching. 

Solution: 

Before induction heating quenching, the preparation work before heat treatment, such as continuous forging, normalizing, annealing, etc., is carried out to make the microstructure of the heated raw material uniform.