Feritscope FMP30 

Chemical, energy, and processing plants are often subject to heat, aggressive media, and high pressure. These circumstances demand steel with high corrosion and acid resistance that are resilient even at high temperatures. If the ferrite content is too low, then the welded material is susceptible to hot-cracking, if the ferrite content is too high, the toughness, ductility as well as the corrosion resistance of the steel are reduced. For duplex steel, a ferrite deficit in the area of the weld seam results in stress corrosion cracking and reduction in strength.

The FERITSCOPE FMP30 measures the ferrite content in austenitic and duplex steel according to the magnetic induction method. All magnetizable structure sections are measured i.e., in addition to delta‑ ferrite also strain‑induced martensite, for example, or other ferritic phases.
It is suited for measurements according to the Basler‑ Standard and according to DIN EN ISO 17655. Areas of application are onsite measurements, e. g. of austenitic plating’s as well as weld seams in stainless steel pipes, containers, boilers, or other products made of austenitic or duplex steel.
Duplex steel is used increasingly in the chemical and petrochemical industries, e. g., for boilers and pipelines. A ferrite deficit in the weld seam area leads to strength reduction, an excess ferrite content to a reduction in toughness and ductility.
When welding duplex steel, the ferrite content in the welding area can easily assume unfavorable values either due to unsuitable welding filler materials or through poor heat input or heat removal. Only an onsite measurement can provide the assurance that the processing did not change the optimum ferrite content in an unfavorable manner at the expense of mechanical or corrosion‑resistance properties.