Background. The first duplex casting was carried out at Avesta in Sweden in 1930, when the idea of ​​duplex stainless steels was brought up for discussion within industries. Over the past 30 years, duplex steels have undergone remarkable development and have been used significantly. The evolution of steel manufacturing techniques mainly affected this take-off. Duplex stainless steels are a combination of many of the beneficial properties of ferritic and austenitic steels. Early duplex steel grades had excellent performance characteristics as well as limitations. The metallurgical processes of the time were not suitable for producing grades with a good austenite-ferrite balance. These early duplex steels also had high carbon content due to the unavailability of effective decarburization techniques. Due to these limitations, products using these materials were limited to specific applications. (Alvares-Armas, 2008) Advances in processing techniques in the late 1960s and early 1970s led to the manufacture of modern duplex steels. The introduction of vacuum and argon-oxygen decarburization (VOD and AOD) was the main factor leading to this massive development of duplex steels during this period. Thanks to advances in these techniques, it has been possible to obtain low carbon steels mixed with high contents of nitrogen and chromium in balance with austenite and ferrite. This eliminated many of the defects of older duplex steels. The alloy content provides corrosion resistance while the duplex microstructure helps prevent chloride stress cracking in harsh conditions. And these duplex steels also had good welding ability. Modern duplexes were used for offshore and nearshore industries where conditions are severe and ...... middle of paper ...... cutting which uses a flame torch using oxygen and associated propane Iron powder is also used to cut steel. This method is clean and fast. Plasma jet cutting is another method that uses a column of ionized gas in conjunction with an electric arc through a small orifice. The gas produces extremely high temperatures to melt the metal. (Chater, 2010)FinishingFinally, the surface is finished to required standards using several methods.Type of finishing MethodDull finish Hot rolling, annealing and descalingBright finish First hot rolling then cold rolling on polished rollsHighly reflective finishing Cold rolling in combination with annealing a controlled atmosphere furnace, by grinding with abrasives or by polishing a finely ground surface. Mirror finish Polishing with progressively finer abrasives, followed by further polishing