Flame cutting method for high-grade wear-resistant steel plates

This is as simple as cutting ordinary low-carbon and low alloy steel. When cutting wear-resistant steel plates and thick plates, attention should be paid!!! As the thickness and hardness of the steel plate increase, the tendency for cracks to appear at the cutting edge increases. To prevent the generation of steel plate cutting cracks, the following suggestions should be followed during cutting:
Cutting cracks: Steel plate cutting cracks are similar to hydrogen induced cracks generated during welding. If cracks occur during steel plate cutting, they will only appear within 48 hours to a few weeks of cutting thickness. Therefore, cutting cracks belong to delayed cracks, and the greater the thickness and hardness of the steel plate, the greater the occurrence of cutting cracks.
Preheating cutting: The most effective method to prevent steel plate cutting cracks is to preheat before cutting. Before flame cutting, the steel plate usually needs to be preheated, and the preheating temperature mainly depends on the quality grade and thickness of the steel plate, as shown in Table 2. The preheating method can be carried out using a flame burner, an electronic heating pad, or a heating furnace. To determine the preheating effect of the steel plate, the required temperature should be tested on the hot spot surface.
Attention: Special attention should be paid to preheating to ensure that the interface between the two steel plates is evenly heated to avoid local overheating in the area in contact with the heat source.
Low speed cutting: Another way to avoid cutting cracks is to reduce the cutting speed. If full page preheating is not possible, the local preheating method can be used instead. The use of low-speed cutting methods to prevent cutting cracks is not as reliable as preheating. We suggest using a flame gun to pre heat the cutting strip several times before cutting, with a preheating temperature of around 100 ° C. The maximum cutting speed depends on the grade and thickness of the steel plate.
Special note: Combining preheating and low-speed flame cutting methods can further reduce the probability of cutting cracks.
Requirements for slow cooling after cutting: Whether preheating or not is not necessary for cutting, the slow cooling after steel plate cutting will effectively reduce the risk of cutting cracks. If it is left warm and not visible after cutting, covering it with an insulation blanket can also achieve slow cooling, which requires cooling to room temperature.
Heating requirements after cutting: For the cutting of wear-resistant steel plates, immediate heating (low-temperature tempering) is also an effective method and measure to prevent cutting cracks. Steel plate cutting thickness can effectively eliminate cutting stress through low-temperature tempering treatment (low-temperature tempering process; insulation time: 5min/mm)
For the method of heating after cutting, combustion guns, electronic heating blankets, and mourning furnaces are also used for heating after cutting.