UGIPERM® 12FM Solution-Annealed Stainless Steel – High Permeability, Low Coercivity

The UGIPERM® 12FM grade can be used for conventional cold-working processes (wire drawing, bar drawing or forming). However, the metal cannot be significantly cold deformed due to its sulphur content that does not allow it to exceed a 40 % section reduction. The mechanical characteristics increase slightly during cold deformation. The loads on the tools are limited.

Overall general corrosion

UGIPERM® 12FM has good corrosion resistance in water and in slightly acid and mildly chlorinated environments. Tests performed in various slightly aggressive environments showed that the corrosion resistance of UGIPERM® 12FM was similar to that of 430FR / 4105Si. The environments to be avoided are phosphoric acid, saline environments, sulphuric acid, sea water, acetic acid and petroleum environments.

UGIPERM® 12FM was subjected to the CM85A test developed by the Society of American Engineers (SAE). The test evaluates the corrosion resistance of a metal in a synthetic gasoline type environment in which, in addition, the chloride content is varied. This environment consists of a mixture of 850 ml ethanol, 75 ml iso-octane, 75 ml toluene, 1 ml distilled water and 0.005 g NaCl (3 ppm) and 0.05 ml formic acid (60 ppm). The test was performed at several chloride levels, as shown on the graph on the right side of the material page and indicates the similar behaviour of UGIPERM® 12FM and 430FR / 4105Si.

Localised corrosion - Pitting corrosion with neutral salt spray test / ASTM standard B117

This test involves spraying a sodium chloride solution, 5% by mass (0.86 moles/litre of NaCl at 35°C, neutral pH) into an enclosure. The exposure time after which the first corrosion spots and run-outs appear is determined visually. The result of this test greatly depends on the grade, as well as on the surface finish tested.

UGIPERM® 12FM provides reasonable resistance to the salt spray corrosion test (ASTM B117). It will rust before 300 hours of exposure, but will nevertheless withstand corrosion far better than Fe-Si magnetic steels.

Thanks to its high sulphur content, UGIPERM® 12FM offers a high level of machinability, similar to those of grades UGI4105Si, UGI4106 or even UGI4114. Therefore, contrary to what is commonly observed on ferritic stainless steel with a low or medium sulphur level, the phenomenon of chips sticking to the cutting tools is unusual with UGIPERM® 12FM. This makes it easier to guarantee the dimensions of the machined parts and to ensure that the surface finish of the components is of very high quality. Finally, the excellent chip breakability of UGIPERM® 12FM prevents machine outages due to chip entanglement which are commonly encountered when bar turning ferritic grades with a lower sulphur content.

The UGIPERM® 12FM grade can easily be forged at high temperatures between 850°C and 1150°C. The heating temperature must not exceed 1150°C to prevent excessive grain growth. This grade can more easily be transformed and is more ductile than austenitic stainless steels. The stamping loads on UGIPERM® 12FM parts will be minimal. The material can be used to manufacture thin-walled parts, due to its good ductility.

Available products:

For other types, please contact the supplier.

UGIPERM® 12FM can be welded by most arc welding processes (MIG/TIG, with or without filler metal, coated electrodes, plasma, etc.), by laser, resistance (spot or seam), friction or electron beam welding. However, its high sulphur content could cause a varying degree of porosity formation in weld metal zones, depending on the welding technique and parameters used. Moreover, its 100% ferritic character makes UGIPERM® 12FM potentially sensitive to intergranular corrosion in the heat-affected zone (HAZ), as well as in the weld metal zone, in the event of homogenous welding with or without the use of homogenous filler material. Welding techniques (LASER, electron beam welding, etc.) that allow weld metal zones to cool very quickly after welding are therefore recommended to limit the risk of the formation of chromium-depleted areas at grain boundaries in the weld metal zone.