Slag
Slag refers to melted and re-solidified material deposits adhering to the cut edges of sheet metal components.
It arises primarily during thermal cutting processes such as plasma or oxyfuel cutting and affects subsequent edge and surface processing.
Formation of slag
Slag forms when molten material is not completely removed from the cut during the thermal cutting process. The remaining molten material solidifies on the underside or along the cut edge of the component.
Factors influencing slag formation
- Separation process
- Sheet thickness
- process parameters
- Cutting speed
- Heat input
Effects on edge processing
Remaining slag can impair stable subsequent processes and lead to uneven tool engagement. Particularly during pre-grinding and deburring, heavy slag formation increases tool wear and makes reproducible material removal more difficult.
Potential impacts on quality
- Impaired coating ability
- Assembly problems due to adhering residues
- Process instability in subsequent processing steps
- uneven edge quality
Influence of slag on subsequent processes
Remaining slag not only affects direct edge processing but also subsequent industrial manufacturing processes. In particular, uneven material adhesion leads to unstable tool engagement and makes it difficult to achieve a reproducible component condition.
In automated machining processes, heavy slag formation can lead to fluctuations in material removal. This alters edge quality, surface condition, and machining stability throughout the entire manufacturing process.
Typical effects in subsequent processes
- unstable tool engagement during pre-grinding
- increased tool wear
- uneven edge rounding
- Impairment of coating capability
- increased rework effort
- unstable process conditions in automated systems
Differences depending on the separation method
The composition of slag varies depending on the thermal cutting process used. Heat input, cutting speed, and material thickness influence the shape, adhesion, and hardness of the material deposits.
Typical differences
- Plasma cutting: often, heavier slag deposits are found at the bottom edge
- Autogenous cutting: high thermal stress and coarse material adhesion
- Laser cutting: depending on the cutting gas and process control, different burr and slag formation occurs
Slag removal as a process step
In the slag removal process step, mechanical tools are used to remove coarse material adhesions and molten residues from the cut edge in a controlled manner. This creates a homogeneous starting condition for subsequent processing steps such as pre-grinding, deburring, and edge rounding.
FAQ
Which processes produce slag?
Slag is primarily produced during thermal cutting processes such as plasma and oxyfuel cutting. In laser cutting, it can occur in varying degrees depending on the process parameters, material, and cutting gas.
Why does slag need to be removed?
Remaining slag affects edge quality, increases tool wear and can impair stable subsequent processes such as coating, welding or assembly.