Heat Treatment Process of HSS Rolls (High Speed Steel)

The performance of high-speed steel rolling rolls is not only related to chemical composition and manufacturing process, but also to heat treatment process.

Due to the high content of alloying elements in high carbon and high vanadium high-speed steel, coupled with its high carbon content, multiple crystalline phases, and complex structure, the heat treatment process is significantly different from ordinary high-speed steel.

In addition, HSS rolls have high quality and high internal stress in the workpiece. If the same heat treatment process as high-speed steel tools is used, the rolls are prone to cracking. Therefore, it is not feasible to copy the heat treatment process of high-speed steel tools in the heat treatment of HSS rolls.

The founder Mr. Gong and others studied the effects of quenching and tempering treatment on the microstructure and properties of HSS rolls containing 1.6% -2.0% (C), 0.3% -1.0% (Si), 0.3% -1.0% (Mn), 1.5% -2.5% (W), 4.0% -8.0% (Cr), 4.0% -6.0% (Mo), 3.0% -5.0% (V), 0.5% -1.5% (Nb), and 0.5% -1.5% (N).

When the quenching temperature is 1150 ℃ and the tempering temperature is 550 ℃, there is a hardening phenomenon in the HSS rolls, and the hardness after tempering is 3 HS higher than that after quenching. No matter what temperature is used for quenching and tempering, the hardness decreases, especially when tempering at 600 ℃. The decrease in hardness is significant. Although the hardness also decreases during quenching at 950 ℃ and tempering at 500 ℃, the final hardness can still reach 83 HS.

Based on the above experimental results, two heat treatment schemes are proposed:

1. Quenching at 1150 ℃ and tempering at 550 ℃;

2. Quenching at 950 ℃ and tempering at 500 ℃.

Cited books: Manufacturing Technology of High Speed Steel Roll