Wear-resistant and high-temperature chrome carbide wear-resistant plates with a thickness of more than 50mm are generally cut by flame cutting, also called oxygen cutting. The process is roughly as follows:
(1) Install a cutting nozzle with an appropriate aperture according to the thickness of the high wear-resistant and high-temperature-resistant chromium carbide wear-resistant plate;
(2) Adjust the pressure of oxygen and gas to the specified value;
(3) Ignite the preheating flame with a cutting igniter, then slowly open the preheating oxygen valve, adjust the length of the white heart of the flame, make the flame a neutral flame, and preheat the cutting point;
(4) Only the preheating flame is used to heat the cutting starting point. The cutting nozzle is perpendicular to the surface of the high wear-resistant and high-temperature resistant chromium carbide wear-resistant plate. , 4+4, 5+5) wear-resistant lining plate, wear-resistant plate surface 1.5 ~ 2.5mm;
(5) When the starting point reaches the combustion temperature (bright red), open the cutting oxygen valve, and the cutting can be carried out instantly;
(6) After confirming that it has been cut to the lower surface of the high wear-resistant and high-temperature-resistant chromium carbide wear-resistant plate, move the cutting nozzle at an appropriate speed along the cutting line to continue cutting;
(7) When the cutting is finished, first close the cutting oxygen valve, and then close the oxygen valve of the preheating flame.
1. Cut to length
The cut-to-length method includes touch ball cut-to-length and off-line cut to length:
(1) Touch the ball to measure the size
(2) That is, the fixed-length pulse signal of the cutting machine is sent by the fixed-length bumping ball, but due to the poor conductivity of the oxide scale on the surface of the billet, although the bumping ball is encountered, it is not necessarily in good contact. The machine speed signal is integrated to calculate the length of the blank, and compared with the fixed-length signal to ensure the accuracy of the fixed-length signal.
(3) Off-line cut-to-length cutting
(4) Using a special off-line high wear-resistant and high-temperature resistant chromium carbide wear-resistant plate length measuring device, according to the principle of hot billet heat radiation, the area of the billet in the guide rail is locked by the probe. When the billet enters the area and After occupying the entire area, a fixed-length signal is issued, and then a cutting command is given.
Second, the three conditions of oxygen cutting:
Metal materials should meet the following three conditions for oxygen cutting:
1) The melting point of the oxide produced by the combustion of the metal should be lower than the melting point of the metal, and the fluidity should be better.
2) The ignition point of the metal should be lower than the melting point.
3) When the metal is burned in the oxygen flow, a large amount of heat can be released, and the thermal conductivity of the metal itself is low.
Metals that meet the above gas cutting conditions are pure iron, low carbon steel, medium carbon steel, low alloy steel and titanium. Other commonly used metal materials such as cast iron, stainless steel, aluminum and copper cannot be cut with oxygen because they do not meet these three conditions. The commonly used cutting method for these materials is plasma arc cutting.