阎岩, 郝彦英, 刘献达. An Analysis and Process Improvement on Hole-Defect of Hot-Rolled Billet of Non-Quenched and Tempered Bainite Steel FAS2225[J]. Special Steel, 2018, 39(2): 41-43.
阎岩, 郝彦英, 刘献达. An Analysis and Process Improvement on Hole-Defect of Hot-Rolled Billet of Non-Quenched and Tempered Bainite Steel FAS2225[J]. Special Steel, 2018, 39(2): 41-43.DOI:
The production flowsheet of steel FAS2225 (/%: 0.26C
0.35Si
1.99Mn
0.013P
0.046S
0.54Cr
0.12V
0.02Mo
0.08Ni
0.0012O
0.0070N) is pretreated hot-metal-60t top and bottom combined brown converter- LF-VD-300mmx360mm bloom casting-continuous rolling. The hole formed by center crack of 215mmx213mm rolled billet occurs. And it is obtained by analysis that the thermal stress and structure stress produced by larger heating speed and temperature gradient of casting bloom lead to cracks of bloom and forming hole-cracks of billet during rolling process. By decreasing the heating temperature of bloom at preheating zone in heating furnace from 900℃ to 750℃
prolonging heating time and decreasing temperature gradient from △200℃ to △100℃
it is available to inhibit the formation of hole-defects.