Masteel, the global steel experts, have enhanced their metal fabrication services by offering a new high precision plasma cutting facility. The new equipment uses technology with a smaller nozzle and thinner plasma arc to offer sharp cut edges and high precision bolt holes with little or no finishing required. Plasma cutting is often used in fabrication and construction due to its high speed and precision cutting combined with relatively low cost. Masteel are specialists in large-scale industrial CNC (cut and contour) applications and can handle plasma cutting of alloy steels from stainless to mild steel in thicknesses from 50mm to 64mm respectively. Plasma cutting uses gas heated by an electric arc (50-400 amps) to provide a focused plasma beam (highly energetic mixture of atoms and ions) capable of melting metal rapidly. A combination of high energy plasma, and the pressure of the stream of gas provides the cutting mechanism. The plasma beam melts through the thickness of the steel and the pressure of the gas pushes the molten metal aside. In general plasma cutting is preferred for the cutting of mild and stainless steels as well as copper because of the oxides formed in flame cutting that hamper the cutting process.
Advantages
In the past, there were problems with profiles cut with plasma systems including imprecise edges and bolt holes. The new plasma technology is a total ‘game changer’ for Masteel plasma cutting services.
- Conveys less heat into the profile steel and this results in a reduced Heat Affected Zone on the cut edges
- Provides a cleaner cut dross free edge and precise bolt holes
- Cuts smaller holes due to a lower kerf (width of cut)
- Usually used in flatbed methodology in 2D and 3D modes where complex profiles can be cut with the aid of a computer controlled bed and plasma nozzles
Next generation plasma cutting
Masteel’s profiling services for high carbon alloy steels have been enhanced by the installation of a RUR3500p technology table from Kerf fitted with a Lincoln Electric Spirit II 400amp plasma cutting system.
Cutting control for high quality
The RUR 3500 technology table is a rigid lightweight structure, which has a frame that is distressed and optimised prior to fitting its linear bearings for smooth and precision operation. The frame also runs on rails independent of the cutting bed allowing its isolation from the shock of loading and unloading of plates to retain high precision. The quality of the profiles produced from this setup comes from its motion control system, which utilises twin side drives for high precision and smooth movement synchronised by the Burny 10 LCD Plus control system. The precision of the INOVA torch height control system is also essential to cost effective production as this allows multiple profiles to be cut at one time. The RUR machine will allow Masteel to configure the machine widths and lengths to customer’s specific requirements in dimensions up to 12,000 × 3,000 mm. The system may also be configured for single plate processing or extended to enable pendulum loading with multiple plates. The RUR3500 is ideal for control and quality in plasma cutting.
Precise plasma cutting
Masteel chose the Spirit II 400 Plasma Unit for their plasma cutting system because of the outstanding cut quality and low operational costs. The edge quality that can be achieved by this unit is virtually dross-free with bevels of 2° or less and it uses 78% less gas than comparable units on the market. The unit combines the accuracy and precision of Fine Line technology for a narrow ‘kerf’ with advanced torch technology for a stable plasma column and optimised plasma gas flow. The system is capable of producing precise, square and virtually dross free cuts in materials of up to 75mm thickness. For cutting stainless and mild steel there is the added benefit of UltraSharp Hole cutting technology for outstanding bolthole and slot precision (superior cylindricity and repeatability). This system can produce 3/4:1 bolt-holes in mild steel from 6 mm to 25 mm and 1:1 bolt-holes in mild steel from 3 mm to 25 mm with ultimately no limitations for non-standard hole sizes (it can allow tags for ease of assembly) and greater cutting amperage flexibility. UltraSharp cutting technology uses fully automatic configuration of the cutting parameters through the seamless integration of the BURNY® controllers, SPIRIT® II plasma systems and INOVA® torch height control. UltraSharp Cutting technology applies the most appropriate cutting speeds and feeds for slots, internal cut-outs, and holes without manual programming. The UltraSharp process provides a considerable advantage to Masteel in improving product design and quality.
Conclusion
The new RUR/Lincoln Electric plasma cutting technology installed by Masteel is a ‘game changer’ for the production of high quality steel profiles in a range of configurations. With high precision, low dross cut edges and high-quality bolt holes the advantages and low costs of plasma cutting are available from Masteel now.
References
- Making Plasma Cutting Easier – Using CNC Automation Technology by Brad Thompson and Kris Hanchette, The Fabricator, August 2003.
- http://www.lincolnelectriccutting.eu/en/products/plasma-cutting-systems/
- Sacks, Raymond; Bohnart, E. (2005). “17”. Welding Principles and Practices (Third ed.). New York: McGraw_Hill. p. 597. ISBN 978-0-07-825060-6.