This invention provides a cost-effective hot-dip galvanization process for ferrous metals, which is regardful to the environment and to the health of the personnel.

This invention provides a cost-effective hot-dip galvanization process for ferrous metals, which is regardful to the environment and to the health of the personnel.

Provided is a method for manufacturing a micropore filter usable as SCE. Stainless steel particles having particle diameters of 3 to 60 m are subjected to milling in a bead mill using zirconia beads to prepare powder having a flakiness of 0.03 to 0.4. The zirconia adhered to the surface of the powder is removed by pickling. A load of 10 to 15 kN is applied to 0.5 to 1.0 g of the pickled powder, thereby compacting the powder into a columnar compact body. The compact body is kept and fired in a vacuum atmosphere of 10.sup.5 to 10.sup.3 Pa at a temperature of 1000 to 1300 C. for 1 to 3 hours to form a sintered body. The sintered body is pressed into a pipe having an inner diameter of 0.90 to 0.99 times of the outer diameter of the sintered body, and extruded to obtain a micropore filter.

The present invention relates to a procedure for finishing stainless steel parts. The finishing process of the invention is particularly useful for stainless steel parts of complex structure such as those produced by additive manufacturing of metals.