How to prevent steel plate cutting cracks

When cutting thick plates of wear-resistant steel plates, with the increase of the thickness and hardness of the steel plate, the tendency of cracks at the cutting edge will become greater and greater. In order to prevent the occurrence of steel plate cutting cracks, the following methods can be followed when cutting.

① Preheating cutting: the most effective way to prevent steel plate cutting cracks is to preheat before cutting. The preheating temperature should reach about 100℃, and the maximum cutting speed depends on the steel plate grade and thickness. The preheating method can be flame torch, electronic heating pad or heating furnace. To determine the preheating effect of the steel plate, the required temperature shall be tested at the back of the heating spot.

② Low speed cutting: Another way to avoid cutting cracks is to reduce the cutting speed. If overall preheating is not possible, local preheating method can be used instead. Low speed cutting method is less reliable than preheating to prevent cutting cracks.

(Note: The combination of preheating and low-speed flame cutting methods can further reduce the probability of cutting cracks.)

Requirements for slow cooling after cutting: slow cooling after steel plate cutting can effectively reduce the risk of cutting cracks. Slow cooling requires cooling to room temperature.

Heating requirements after cutting: heating (low temperature tempering) immediately after cutting wear-resistant steel plate is also an effective method and measure to prevent cutting cracks. The cutting thickness of steel plate is tempered at low temperature, which can effectively eliminate the stress involved in cutting.