Abstract: According to analysis on cold upsetting crack of 0. 45C steel φ10 mm rolled products produced by 40 t LD- ladle argon blowing- CC- high speed rod mill process flow sheet at New Fushun Steel, it was obtained that the inclusions Al₂O₃, MnS and the lamellar pearlite in steel were main reason to form cold upsetting crack. With decreasing the sulphur content in charge, decreasing ［S］from 0. 029% to 0. 020%，controlling LD end ［C] and decreasing end [O] , spheroidizing annealing rolled products to increase elongation of steel from original 21. 6% to 30. 4% , the formation of cold upsetting crack was avoided.

Key words: 0. 45C Steel, LD, Ladle Argon Blowing, Cokl L psetting Crack, Process Improvement

摘要： 通过对新抚钢40 t LD-钢包吹氩-CC-高速线材轧制的φ10mm 45钢冷镦裂纹的分析,得出钢中Al₂O₃、MnS夹杂和片状珠光体组织是冷镦裂纹产生的主要原因。通过采用降低炉料中的硫含量使[S]从0.029%降至0.020%,控制LD终点[C]和降低终点[O],轧材经球化退火后钢的伸长率从21.6%提高到30.4%等措施,避免了冷镦裂纹的发生。

关键词: 45钢, LD, 钢包吹氩, 冷镦裂纹, 工艺改进