Oxygen and acetylene gas steel cutting is a normal operation in industry, and its feasibility has been verified by technical parameter and economy. According to the American Welding Society (AWS) standard, oxy-acetylene cutting flame cutting temperature is 3100°C-3300°C (volume ratio of oxygen to acetylene 1.15:1), cutting carbon steel in the range of 1mm-300mm thickness, cutting speed proportional to the inverse of thickness – for example, cutting speed of 6mm steel plate is 600mm/min±5%. 50mm steel plate down to 150mm/min. Measured data from a shipyard show that oxygen and acetylene gas cutting of 20mm thickness Marine steel plate (Q235B) consumes oxygen 3.2m³/h and acetylene 0.85m³/h and costs about 18/ h, 28% lower than plasma cutting (25/ h). The accuracy error, however, is ±0.5mm (plasma is ±0.2mm).
Technical parameters directly affect cutting quality: oxygen pressure should be kept constant at 0.4-0.6MPa (up to 0.8MPa in case of cutting thickness > 50mm), acetylene pressure 0.03-0.07MPa. If the flow rate of oxygen is too low (< 8L/min), the preheating time is increased from 15 seconds to 40 seconds, and the thickness of the incision oxide layer is increased to 0.3mm (normally 0.1mm), resulting in a 35% increase in the cost of subsequent grinding. According to the 2022 accident analysis of a German steel structure plant, the excessive oxygen pressure (0.9MPa) made the tempering frequency rise 4 times, the notched heat affected zone width was expanded to 4mm (normal 1.5mm), and the material tensile strength was reduced by 12%.
Safety standard and risk control: acetylene cylinder must conform to the DOT-8AL standard (explosion limit 2.5%-81%), and the oxygen cylinder pressure gauge must be 0-25MPa (error ≤±1.5%). According to the US Occupational Safety and Health Administration (OSHA), the accident rate of oxyacetylene cutting equipment without a tempering preventer is up to 1.2 times per thousand hours, while compliance equipment is only 0.15 times. In 2021, a Texas metal processing factory caused an explosion due to acetylene leakage (concentration > 1.5%) with a direct loss of 2.4 million yuan and was forced to replace with the ISO5172 standard explosion proof cutting torch (unit price 350, which is 40% higher than the ordinary model).
Economic comparison and alternatives: For plates of medium and thick (20-100mm), oxygen and acetylene gas cutting equipment investment (1,200) is only 0.8% of the laser cutting machine (150,000), but the efficiency is 60% lower (80m vs. 200m daily cutting volume). In cutting stainless steel or aluminum alloy, oxy-acetylene cannot be applied due to excessive oxidation (chromium loss rate > 15%) and plasma cutting has to be used (cost 0.3/m, oxygen acetylene is 0.1/m but cannot achieve the standard). A Chinese agricultural machinery factory estimates that below 5,000 meters per year, the total cost of oxyacetylene program is 42% lower than plasma, but above 10,000 meters, due to the frequent replacement of consumables (nozzle life 500 hours vs. Plasma 1,200 hours), the cost advantage is lost.
Environmental and operational limitations: oxy-acetylene cutting produces CO concentration of 300-500ppm (OSHA limit 50ppm), requiring ventilation systems (wind speed ≥1m/s), which increases 6/ hour to the cost of energy consumption. High carbon steel (with C > 0.312/m). The case of the Norwegian Arctic research station illustrates that at -30 ° C, oxygen and acetylene gas cutting efficiency is reduced by 55% (acetylene gasification is insufficient), while low temperature plasma equipment (-40 ° C) remains 85% efficient, but the unit price of the equipment is 8 times higher.
Depending on adaptation technique to economic trade-offs, whether one can use oxygen and acetylene gas to cut carbon steel or not is contingent upon the thickness range (1-300mm), the size of the budget, and the working environment. It is suggested by ASTM that the oxide flame (oxygen ratio 1.3:1) and G01-30 cutter nozzle (0.9mm aperture) together can keep the cutting surface roughness (Ra) of 12mm steel plate under 25μm as per the ISO 9013 standard. For tolerances of < ±0.3mm accuracy or for non-carbon steels, the whole life cost of alternative cutting technologies such as laser/plasma should be assessed.