Plasma cutting can be used to cut any type of conductive material including stainless steels and carbon steels as well as aluminum, copper, brass and cast metals. The plasma cutting process is intensely heated and cooled to produce different results for each material.
Mild steel is the most common material used in metal fabrication, briefly explained here some of the best plasma cutters under 500 bukcs. These materials are attractive because of their corrosion resistance, high strength to weight ratio, thermal properties and aesthetics. It has been documented that plasma-cut carbon steels can be welded and have other material properties. Engineers from the author’s firm published a recent study in The FABRICATOR(r), September 2000, pages 28-31. This study characterized the heat affected zone (HAZ), for carbon steels. They also suggested alternative plasma processes to reduce HAZ. Scientists have continued to study the material properties in stainless steels as well as aluminum. These two objectives were to characterize chemical and thermal changes in plasma-cut stainless and aluminum alloys. Recommend process alternatives that may improve aesthetics and cut quality to improve forming and fabricating of these materials.Water-injection PAC (WIP). This procedure uses plasma-forming gas and water injection. To constrict the plasma jet and protect the torchnozzle, injection water is directly applied to it. A nitrogen plasma water-injection device was used for this experiment.
Conventional Dual-gas PAC. This involves a plasma-forming gas, and a shield gaz that helps in cutting quality. For this experiment, several plasma and shield gas combinations were used: air plasma-air shield, nitrogen plasma-nitrogen shield, nitrogen plasma-carbon dioxide shield, and argon/hydrogen plasma-nitrogen shield.High-precision PAC (HPP). The process involves a strong vortex, which is plasma gas, and specific consumable geometries. This allows for greater energy density and arc constrictions. In this experiment, argon/hydrogen-plasma-nitrogen shield and air plasma-air methane were used.
The thickness of the cut samples varied from 1 to 25mm. The operating conditions are summarized in Figure 1. Each cut sample was removed by researchers (see Figure 2) The microstructure was revealed by electrochemically etching the section. Microstructure is a term that refers to the microstructure of a material. This structure determines many of its physical characteristics.
Using optical microscopy, measurements and analyses were taken of each cut sample. Two magnifications were used. One, 100, which allows measurement of HAZ features; and, 400 to 500 which allows for analysis of HAZ phases. Materials used
The majority of the samples were cut from sheets made of 304 SS. A limited number of martensitic 410 SS samples were also analyzed because 300 series stainless has an Austenitic phase structure. There is a significant difference in the iron and nickel content between 300 and 400 series: 410 SS has a higher iron content (84-86 percent), while 304 SS has significant Nickel content (8 to 10.5%).Due to their chemical compositions, the 300 and 400 series materials have different thermophysical characteristics. These properties can affect the metal’s behavior during cutting and the HAZ. Alloy 6061 is used for aluminum cutting.