X70管线钢控轧控冷工艺与组织性能的关系  

Relationship between Microstructure and Properties of X70 Pipeline Steel and Controlled Rolling and Controlled Cooling Process

作　　者：王春明[1] 吴杏芳[1] 刘玠[2] 黄国建[2] 李桂艳[2] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]鞍山钢铁集团公司,辽宁鞍山114021

出　　处：《钢铁》2005年第3期70-74,共5页Iron and Steel

摘　　要：X70管线钢中针状铁素体的比例随热变形后的冷却速度增加而提高,冷却速度为15 ℃/s时达到最大,冷却速度再增加,该比例变化不大.冷却速度较低时(2 ℃/s)和热变形后的终冷温度较高时(650 ℃)组织中出现珠光体.随着终冷温度的降低,试验钢的组织细化,在500～550 ℃终冷时组织较为理想.铁素体晶内弥散分布有尺寸为20 nm左右的析出相,析出相在位错处择优成核并与基体保持共格或半共格关系.The volume fraction of acicular ferrite in the microstructure of X70 pipeline steel is increased obviously with cooling rate after thermo-mechanical deformation and reaches a maximum at the cooling rate of 15 ℃/s. It varies scarcely at higher cooling rate afterwards. The pearlite emerges in the microstructure of the steel at lower cooling rate(2 ℃/s) and higher finish-cooling temperature(650 ℃). The quite fine microstructure can be got by lowering the finish-cooling temperature of which 500-550 ℃ is better. The around 20 nm precipitate phase can be seen through TEM, which keeps coherent or semi-coherent with the matrix and nucleates preferentially at the dislocations.

关 键 词：管线钢 X70 控轧控冷 针状铁素体 

分 类 号：TG335[金属学及工艺—金属压力加工]