Abstract: Effect of different cooling history on yield ratio of HP295 steel for welded gas cylinder was studied and the result implied that both fine microstructure and good mechanical properties can be attained by using two-stage cooling and controlling the coiling temperature. The yield ratio of HP295 steel sheet was reduced to less than 0.8 by two-stage cooling process. The pass percent of yield ratio was enhanced from less than 90% to 100%. The mechanical properties satisfied the criteria of GB6653-1994.

Key words: HP295 steel sheet, Yield ratio, Two-stage cooling, Coiling temperature