| 摘要 |
PURPOSE:Stainless steel fiber of a specific diameter is subjected to heat treatment for controlling crystal grain sizes and to selective corrosion on the crystal grain boundaries, thus producing the titled short fiber suitably used for an filter element, because of its same diameter and cylindrical form all over the length. CONSTITUTION:Stainless steel fiber of 2-20mu diameter, preferably of 18-8 stainless steel austenite is subjected to heat treatment for controlling crystal grain sizes, preferably at 900-1,400 deg.C in nonoxidative atmosphere, e.g., for 1-3hr. Then, the resultant fiber is dipped in an acidic solution, preferably a mixture of hydrofluoric acid and nitric acid to effect selective corrosion on the crystal grain boundaries to cut the bonds between crystal grains. Thus, short fibers of 2-20mu length, 1-50 aspect ratio (length/diameter) and cylinder with the constant diameter all over the length and no sagging are produced. EFFECT:They have functions as a membrane filter as well as a metal material. |
