How to choose the carbon rod diameter and operating angle in deep groove planing and shallow cleaning?

How to choose the carbon rod diameter and operating angle in deep groove planing and shallow cleaning?

In deep groove gouging and shallow cleaning of carbon arc gouging, the selection of carbon rod diameter and operating angle needs to consider multiple factors. Here are some suggestions:

Selection of carbon rod diameter

Deep groove gouging:

Generally speaking, deep groove gouging requires greater power and heat input to remove more metal materials, so carbon rods with larger diameters are usually selected. Common choices are 6-10mm carbon rods. If the groove is deeper and the material is thicker, consider using 8-10mm diameter carbon rods, which can provide sufficient arc heat to fully melt the metal, making it easier for compressed air to blow it away and improve gouging efficiency. For example, when deep groove gouging metals with a thickness of more than 20mm, 8mm or 10mm carbon rods are more suitable.

For deep groove gouging of some metal materials with higher hardness, larger diameter carbon rods are also required to ensure sufficient energy input. For example, when planing hard materials such as high alloy steel or stainless steel, a 6-8mm carbon rod may be more suitable, which can ensure sufficient heat to melt the metal and avoid arc instability due to the carbon rod being too thick.

Shallow cleaning:

Shallow cleaning mainly removes scale, oil stains, weld defects, etc. on the metal surface, and does not require too much heat input. Therefore, a carbon rod with a smaller diameter should be selected to better control the planing depth and range to avoid excessive damage to the metal matrix. Generally, a carbon rod with a diameter of 3-6mm can be selected. For example, for shallow cleaning of general low-carbon steel or stainless steel surfaces, a carbon rod of 3-4mm can meet the requirements, can accurately remove surface impurities, and will not cause excessive thermal impact on the matrix.

If the cleaning area is large, but the cleaning depth is required to be shallow, a carbon rod with a slightly larger diameter, such as 5-6mm, can also be selected, which can ensure the cleaning effect while improving work efficiency. But pay attention to controlling the current and planing speed to avoid planing too deep.

Selection of operating angle

Deep groove planing:

The angle between the carbon rod and the workpiece surface is usually between 45° and 60°. A larger angle can make the arc more concentrated on the planing area, increase heat input, and facilitate the formation of deep grooves. At the same time, such an angle can also enable the compressed air to better blow the molten metal away from the bottom of the groove and reduce the accumulation of slag. For example, when planing a deep V-shaped groove, the carbon rod angle can be controlled at 50°-60° to ensure that the two sides of the groove are smooth and the bottom is flat.

When the width of deep groove planing is wide, the angle of the carbon rod can be appropriately reduced to about 40°-45°, so that the arc covers a wider range and ensures that the width of the groove is uniform. However, too small an angle may cause arc instability and affect the planing effect, so it needs to be adjusted according to actual conditions.

Shallow cleaning:

The operating angle is generally between 30°-45°. A smaller angle can make the arc energy act more dispersedly on the metal surface, avoiding local overheating. It is also convenient to observe the cleaning effect and accurately control the cleaning range. For example, when performing shallow cleaning on the weld surface, controlling the carbon rod angle at 30° - 35° can effectively remove the slag and oxide scale on the weld surface without causing excessive melting and damage to the weld metal.

If the surface to be cleaned is uneven and has uneven parts, the carbon rod angle can be adjusted according to the specific situation so that the arc can be perpendicular to the surface to be cleaned to ensure uniform cleaning effect. In this case, the angle may be flexibly changed between 30° - 45°.