METHOD FOR PRODUCING A ROLLING SHEET FROM HIGH-MANGANE STEEL WITHOUT A SIMILAR TISSUE

摘要

PCT No. PCT/KR95/00027 Sec. 371 Date Nov. 22, 1995 Sec. 102(e) Date Nov. 22, 1995 PCT Filed Mar. 25, 1995 PCT Pub. No. WO95/26423 PCT Pub. Date Oct. 5, 1995A high manganese steel having superior hot workability is disclosed, in which small amounts of the alloying elements are added into a high manganese steel of Fe-Mn-Al-C system, so that the rupture strength of the grain boundaries of columnar crystals can be improved, thereby realizing an improved hot workability. Further, a process for manufacturing a high manganese hot rolled steel sheet is disclosed, in which the above mentioned high manganese steel is subjected to be controlled the initial hot rolling conditions during a hot rolling, so that large cracks would not be generated on the edges and on the surface of the hot rolled steel sheet. The process for manufacturing a hot rolled high manganese steel without any cracks includes the following the steps. That is, the process includes the steps of: preparing the ingot or the continuous casting slabs of the conventional Fe-Mn-Al-C steel with one or more elements selected from a group consisting of 0.0005-0.04% of B, 0.0005-0.050% of Ti, 0.0005-0.050% of Zr, 0.0005-0.040% of La, 0.0005-0.040% of Ce, and 0.0005-0.030% of Ca; heating the ingot or the continuous casting slab to a temperature range of 1150 DEG -1300 DEG C.; carrying out a hot rolling by applying a low reduction ratio below 7% per pass and an average strain rate below 2.0 sec-1 per pass, until a total reduction ratio reaches 40%; and carrying out a hot rolling by the high reduction ratio after reaching the total reduction ratio of 40%.