Oxyacetylene cutting method

Oxyacetylene cutting methods - ordinary ring-shaped cutting nozzle close to the cutting Chen Weiguo (Zhejiang Province, Shaoxing City, Fu Lida Silk Printing and Dyeing Co., Ltd. 312000) according to the routine, cutting medium-thickness plate, the cutting nozzle and the workpiece should be maintained at a distance of 3 to 5mm, mainly to prevent melting and carbonizing of the edge of the kerf occurs in the cutting process. In practice, the author believes that the cutting nozzle distance can be close to 0.5 ~ 1mm, and even contact with the steel plate. Because theoretically speaking, pure oxygen gas flow from the trans-subsonic orifice out, if the gas pressure increases to 0.5MPa above, the flow rate increases to the speed of sound, there will be a strong shock wave in the gas flow, so that the heat loss, the ejection of gas flow coarsening, transverse expansion, the occurrence of turbulence and lead to the entry of the surrounding gas, thus reducing the purity of cutting oxygen, affecting the cutting speed and quality. Cutting nozzle close to the steel plate after cutting, in fact, is the extension of the exit nozzle, because this extension as far as possible to reduce the theoretical disadvantages. For example, a cut piece thickness of 25mm, according to the conventional need to choose G01-100 type torch, nozzle 1 # or 2 #, oxygen pressure of 0.5 ~ 0.7MPa, and the use of close to the cutting only need to use G01-30 torch, nozzle 3 #, oxygen pressure of 0.4 ~ 0.5MPa. Specific methods of operation: preheating to the red-hot condition In order to prevent the edge of the mouth melting, carbon increase, can be adjusted to small preheating flame, to be pierced after the cutting nozzle vertical drop to 0.5 ~ 1mm from the steel plate. Therefore, when the metal in pure oxygen combustion, itself is also a kind of exothermic process, preheating flame as long as it can ensure smooth cutting can be.