Annealing is a subfield of heat treatment and is one of the manufacturing processes characterized by a change of a material’s properties.
Hardenable steels undergo a structural change in the heat-affected zone during electrical resistance butt welding. A controlled annealing process over several stages (soft annealing) ensures the necessary material properties for the subsequent production process and reduces existing precipitations of cementite or perlite. Typical temperatures for this are 650 °C - 750 °C.
Soft annealing reduces the hardness and strength and thus considerably facilitates further processing steps such as rolling, wire drawing or punching, especially because it prevents the formation of cracks.
Normalizing is carried out at a temperature just above the upper transformation point (maximum 950 °C) with subsequent cooling in a still atmosphere. Above these transformation points the microstructure is completely austenitized.
During cooling, a retransformation to a normal microstructure (in the sense of the iron-carbon diagram) takes place which is largely independent of the initial state, usually consisting of ferrite, perlite and/or cementite, depending on the carbon content. Cooling in a still atmosphere also ensures grain refinement, i.e. the formation of a fine structure.
The V30 smart welding and annealing control
This new control unit generation combines proven functionality with intuitive user guidance using a rotary pushbutton and a large 7” display.
- V30 smart highlights
- Intuitive menu navigation
- Fully backwards compatible
- Import existing welding programmes
- Large 7” display
- USB/Ethernet ports
- External programme selection
- Preheating for large Ø
- PDA interface
Programmable annealing with V30 smart control
The annealing process is controlled by a programme. The programmes use power and time values to achieve an annealing and welding result that can be accurately reproduced. The controller has undergone continuous development and offers users a high level of process reliability and intuitive operating convenience.
Integrated USB and Ethernet connections allow easy and fast exchange of welding programmes between the controllers. Uncomplicated archiving, editing and management of welding programmes. It is also possible to connect a keyboard or scanner.
Existing welding programmes from previous controller versions can also be imported.
The annealing can be time-controlled using up to three segments. This allows for optimal post-treatment of even the most critical materials. Alternatively available are annealing via pyrometer (max. 5 segments), as well as a graphic visualization of the temperature in setpoint/actual temperature curves to ensure optimum process reliability in the thermal post-treatment of high-carbon steel or special alloys.
The V30 smart controller can detect and compensate voltage fluctuations of +/- 8%. The supply frequency is recognized automatically.
The assignment of passwords allows certain areas to be secured against unauthorized access, e.g. changing welding parameters.
Conversion from the V12 / V20 to the new V30 smart can be done by simply replacing the control unit.
User-defined naming of the welding programmes enables the user to employ the company’s in-house designations, alphanumerically in [mm] and [in].