Nb对Q345低M_(o)耐火钢CCT曲线的影响  

Effect of Nb on CCT curves of Q345 low-M_(o)fire-resistant steel

作　　者：万荣春[1,2] 孙锋[2] 付立铭[2] 单爱党[2] Wan Rongchun;Sun Feng;Fu Liming;Shan Aidang(Materials Engineering Department,Bohai Shipbuilding Vocational College,Huludao Liaoning 125105,China;School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]渤海船舶职业学院材料工程系,辽宁葫芦岛125105 [2]上海交通大学材料科学与工程学院,上海200240

出　　处：《金属热处理》2021年第2期25-29,共5页Heat Treatment of Metals

基　　金：辽宁省自然科学基金指导计划项目(20180550659);辽宁省教育厅科学研究经费项目(BHCYL201901);2019年度辽宁省“百千万人才工程”人选科技活动支持项目(2019B14)。

摘　　要：通过测定两种不同Nb含量的Q345级低M_(o)(约0.25 wt%)耐火钢连续冷却转变(CCT)曲线,研究了Nb对Q345低M_(o)耐火钢CCT曲线的影响。试验结果表明,添加Nb元素可以使Q345级低M_(o)耐火钢的CCT曲线向右移动,贝氏体相变临界冷却速度降低,同时降低试验钢奥氏体临界转变温度,抑制奥氏体转变为珠光体,从而有利于贝氏体相变。此外,要获得Q345级低M_(o)耐火钢F+B+P的理想组织,不添加Nb试验钢的最佳冷却速度应在0.28℃/s左右,添加Nb试验钢的最佳冷却速度应在0.14℃/s左右。Effect of Nb on continuous cooling transformation(CCT)curves of Q345 low-M_(o)(about 0.25 wt%)fire-resistant steel was studied by measuring CCT curves of two Q345 steels with different Nb content.The results show that the CCT curve of Q345 low-M_(o)fireresistant steel moves to the right and the critical cooling rate of bainite transformation decreases with Nb addition.At the same time,Nb addition can reduce the critical transformation temperature of austenite and inhibit the transformation from austenite to pearlite,which is beneficial to bainite transformation.In addition,in order to obtain the ideal microstructure(F+B+P)of the Q345 low-M_(o)fire-resistant steel,the optimal cooling rate of tested steel without addition of Nb should be about 0.28℃/s,and that of tested steel with addition of Nb should be about 0.14℃/s.

关 键 词：NB 耐火钢 CCT曲线 

分 类 号：TG142.1[一般工业技术—材料科学与工程]