Chemical, utility and other processing plants are often exposed to heat, aggressive media and high pressure. These circumstances require rust- and acid-resistant steel that can withstand mechanical stress at high temperatures. If the ferrite content is too low, the weld is susceptible to cracking under heat, if the ferrite content is too high, the weld loses its strength and corrosion resistance. For duplex steel, a lack of ferrite in the area of the weld seam is an indicator of susceptibility to cracking under tension or vibration.
The Feritscope from Gardner Co. measures the ferrite content in austenitic and duplex steel according to the magnetic induction method. All magnetic components of the otherwise non-magnetic structure are recognized. Areas of application are on-site measurements, for example, austenitic claddings as well as weld seams in stainless steel pipes, containers, boilers or other products made of austenitic or duplex steel.