Patent ID: 8343367

Claim:
A method of forming a continuous channel for gas discharge on a surface of a casting roll for twin roll strip casting of high Mn steel containing 18-25 wt % Mn without generation of dents, comprising: photoresist application, including applying a negative photoresist imparted with photosensitivity by adding bichromic acid to protein, shellac, or Poly Vinyl Alcohol and with a thickness of 3-10 μm based on a photoresist having a viscosity of 20-40 Ps on an entire surface of a casting roll for twin roll strip casting of high Mn steel containing 18-25 wt % Mn and then conducting drying in a dark room; patterning, including attaching a film, which is printed with a shape of a continuous channel for gas discharge, to the entire surface of the casting roll and then radiating UV light onto the applied photoresist in a dark room, but under weak fluorescent light, or directly radiating laser onto the dried photoresist in a dark room, but under weak fluorescent light, thus forming the shape of the continuous channel for gas discharge; developing, including exposing the surface of the casting roll, which is subjected to the patterning, to light, and then dissolving a portion of the photoresist, which is not photosensitized, using a dilute ammonia solution, which is weakly alkaline, or a 8% bichromic acid solution, to thus remove it; and etching, including etching a metal surface of the casting roll, exposed in the developing, thus forming the continuous channel for gas discharge, wherein the continuous channel for gas discharge on a surface of a casting roll for twin strip roll casting of high Mn steel containing 18-25 wt % Mn is formed to have a width from 400 μm to 500 μm and a depth from 50 μm to 150 μm.