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Technologies
WHAT IS OXY-FUEL CUTTING
OSSITAGLIO
Oxy-fuel cutting is the oldest metal cutting and welding technology there is. The procedure consists in mixing two gases, the Fuel Gas (Acetylene or, more frequently, Propane) and the Oxidizing Gas (Oxygen). When these two gases are mixed, an exothermic reaction is triggered that can produce 3500°C of heat. The two gases can be combined in a chemically neutral manner, i.e. in a stoichiometric ratio, in which case we get what is known as a Neutral flame, the classic blue-coloured flame; if there is excess oxygen, we get what is known as an Oxidizing flame, which tends towards white in colour; and if there is not enough oxygen, we get what is known as a Carbonizing flame, which tends towards red in colour.
When welding, a flame somewhere between neutral and carbonizing is mostly used: the Neutral flame is usually produced when welding ferrous materials using filler metal; and the Carbonizing flame in braze welding applications. In the latter case, the temperature must be lower since Silver- and Aluminium-based filler metals melt at lower temperature than the base metals. In thermal cutting applications, the flame is used at three different settings, marking the three stages of cutting. Neutral flame for the preheating stage; oxidizing flame for the piercing stage; and Neutral-Oxidizing flame for the cutting stage. Therefore, the cutting torch must be suitable for these three stages.
The proportion of the Oxygen-Propane/Acetylene mixture is adjusted by means of a series of manual or automatic valves. Promotec have always produced machines with automatic valve systems. In addition to holding all the various cutting speed parameters based on the thickness of the material to be cut, the standard software also holds all the pressure values and times for the three stages. The use of oxy-fuel cutting technology is acknowledged as a valid method for cutting very thick (over 30/40mm) ferrous materials, while oxy-fuel cutting cannot be used on stainless materials or on aluminium alloys.
When welding, a flame somewhere between neutral and carbonizing is mostly used: the Neutral flame is usually produced when welding ferrous materials using filler metal; and the Carbonizing flame in braze welding applications. In the latter case, the temperature must be lower since Silver- and Aluminium-based filler metals melt at lower temperature than the base metals. In thermal cutting applications, the flame is used at three different settings, marking the three stages of cutting. Neutral flame for the preheating stage; oxidizing flame for the piercing stage; and Neutral-Oxidizing flame for the cutting stage. Therefore, the cutting torch must be suitable for these three stages.
The proportion of the Oxygen-Propane/Acetylene mixture is adjusted by means of a series of manual or automatic valves. Promotec have always produced machines with automatic valve systems. In addition to holding all the various cutting speed parameters based on the thickness of the material to be cut, the standard software also holds all the pressure values and times for the three stages. The use of oxy-fuel cutting technology is acknowledged as a valid method for cutting very thick (over 30/40mm) ferrous materials, while oxy-fuel cutting cannot be used on stainless materials or on aluminium alloys.