Round steel Flame cutting

Round steel is a kind of long steel with a circular cross-section, which is widely used in construction, machinery manufacturing, ships, Bridges and other fields. Its diameter ranges from a few millimeters to hundreds of millimeters, the material covers ordinary carbon steel, alloy steel, stainless steel and so on. In the processing process, the cutting of round steel is one of the basic and key processes, which directly affects the subsequent processing efficiency and the quality of the finished product. This paper systematically introduces the cutting method, process flow, quality control points and practical application of round steel.

According to the material characteristics, processing needs and equipment conditions, the following technologies can be used for round steel cutting: 1. Flame cutting (oxy-acetylene cutting) Principle: The use of oxygen and acetylene mixed combustion to produce high temperature (about 3000 ° C), through the oxidation reaction to melt the metal and blow away the slag. ◦ Application scenario: It is suitable for large carbon steel round steel with diameter ≥50mm, with low cost, large heat affected zone and high cutting surface roughness. ◦ Key parameters: cutting oxygen pressure (0.6~1.0MPa), preheating flame temperature, cutting speed (inversely proportional to thickness). 2. Plasma cutting principle: Form high temperature plasma arc through ionized gas, melt metal and blow away through high-speed airflow. ◦ Advantages: Fast cutting speed (up to 3 times the flame cutting), can handle stainless steel, alloy steel and other refractory materials, smooth incision. ◦ Limitation: High equipment cost, suitable for 20~150mm diameter of medium specification round steel. 3. Laser cutting ◦ technical features: The use of high-energy laser beam focus after gasification or melting materials, the accuracy of up to ±0.1mm, the incision without burrs. ◦ Application: Suitable for precision parts processing, such as high-precision stainless steel round steel with diameter ≤50mm. ◦ Economy: Large initial investment, suitable for mass production scenarios. 4. Sawing (band saw/disk saw) ◦ Mechanical sawing: Carbide saw blade, through mechanical force to achieve cold cutting, no thermal deformation. ◦ Advantage: Stable notch quality, suitable for small batch, multi-specification processing, especially for high hardness alloy steel. ◦ Typical equipment: Horizontal band sawing machine can cut large round steel with diameter ≤600mm.

2, round steel cutting process 1. Preparation ◦ Material inspection: check the material certificate, detect the surface cracks, bending and other defects of round steel. ◦ Equipment commissioning: Select cutting parameters according to diameter (for example, oxygen/gas ratio should be adjusted for flame cutting). ◦ Positioning and fixing: V-shaped clamps or magnetic platforms are used to ensure that the round steel does not roll during cutting. 2. Cutting operation ◦ Example of flame cutting: 1. Preheat: Align the torch with the starting point of cutting and preheat until the metal is molten (about 900 ° C). 2. Open oxygen cutting: open the high-pressure oxygen flow, push the cutting torch at a constant speed, and keep the cutting slit width consistent. 3. End treatment: Reduce speed to avoid section collapse. 3. Post-treatment ◦ Deburring: Use an Angle grinder or file to clean the cut edges. ◦ Straightening: Hydraulic straightening of round steel deformed by thermal stress, the straightness error should be less than 1mm/m. ◦ Anti-corrosion: the cut of carbon steel is sprayed with anti-rust primer, and the stainless steel needs to be acid-washed and passivated. 1. Dimensional accuracy ◦ Length tolerance: ordinary grade ±2mm, precision grade ±0.5mm (laser cutting). ◦ Section perpendicularity: Deviation ≤1° (measured by a square). 2. Incision quality ◦ roughness: flame cutting Ra≤50μm, laser cutting Ra≤12.5μm. ◦ No hanging slag: Plasma cutting must ensure that the slag completely falls off. 3. Material properties protection ◦ Heat affected zone (HAZ) control: flame cutting HAZ width ≤3mm to avoid grain coarsening resulting in strength reduction. ◦ Hardness test: The surface hardness change after cutting does not exceed 10% of the base material.

The selection of round steel cutting technology requires comprehensive consideration of material characteristics, processing accuracy, cost efficiency and environmental protection requirements. With the advancement of intelligent manufacturing and green processes, high-precision and low-energy cutting methods will become the mainstream. In the future, the optimization of cutting paths through AI algorithms and the development of new composite cutting technologies (such as laser-plasma composite) will further improve the quality and efficiency of round steel processing.