Overpickled surface - 1.4305 steel - Cold drawing defects

Overpickled surface - 1.4305 steel - Cold drawing defects

Figure 1: Treatment: Solution annealed. Magnification: 6.5x. Sampling/Specification: Wire surface. Testing result: Strong scarred surface.

Figure 2: Treatment: Solution annealed. Magnification: 25x. Sampling/Specification: Wire surface. Testing result: Scars and grain boundary attack.

Defect name: Overpickled surface
Record No.: 494
Type of defect (Internal/Surface): Surface
Defect classification: Cold drawing defects
Steel name: 1.4305 steel
Steel composition in weight %: No data.
Note: The grain boundary attack occurs at high alloyed, austenitic or ferritic, chromium and chromium nickel materials, under unfavorable conditions at the pickling. Predominantly carbide precipitates on the grain boundaries are responsible for this corrosion form. The grain boundary attack can lead fast to intercrystalline corrosion if the material to be pickled was heat treated for example badly, the pickling agent shows a not suitable composition, or the pickling time is too long. In this case the material was pickled too long.
Rod wire 8.00 mm round - solution annealed.
Reference: Not shown in this demonstration version.