X70针状铁素体管线钢析出相  

Precipitates in X70 pipeline steel

作　　者：王春明[1] 吴杏芳[1] 刘玠[2] 徐宁安[1] 

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,鞍山114021

出　　处：《北京科技大学学报》2006年第3期253-258,共6页Journal of University of Science and Technology Beijing

摘　　要：用透射电镜研究了 X70针状铁素体管线钢中的析出相．一种是以 TiN 为主、尺寸较大 (50nm～1μm)、外形规则、几乎呈立方体的 Ti(Nb)NC 复合析出相,其中 Ti／Nb 比值处于5～12之间．另一种是以 NbC 为主、尺寸十分细小(小于20nm)、形态为圆形或椭圆形的 Nb(Ti)C 复合析出相,Nb／Ti 比值处于1～6．37之间,衍射分析结果表明其为多晶粒构成．分析表明,尺寸较大的方形析出相在1150℃的温度时已经存在,并且在热模拟过程中变化不大．细小圆形析出相绝大部分是在1100～900℃之间析出,而且与基体保持共格或半共格的关系．V 的析出不明显,其作用相对较弱．高温热塑性曲线的测量结果显示,在没有变形情况下,1050℃时析出相开始析出,900～850 ℃之间析出量达到最大．The precipitates in X70 acicular ferrite pipeline steel were investigated by transmission electron microscope. There are two typical precipitates in X70 pipeline steel. One is cubic shaped compound precipitates Ti（Nb）NC with the size of 50 nm- 1 μm, in which TiN plays the main role and the ratio of Ti/ Nb reaches 5-12. The other is spherical shaped Nb（Ti）C with the size less than 20 nm, in which NbC is the main phase with the ratio of Nb/Ti within 1--6.37. The spherical shaped precipitates exist in multigrains proved by electron diffraction. The cubic shaped precipitates formed above 1 150 ℃, and varied scarcely during the process afterwards. The spherical （ellipsoidal） shaped precipitates emerged almost totally in the range of 900 ℃ to 1 100 ℃, and kept coherent or semi-coherent relationship with the matrix. The precipitate of V was not obviously observed reminding the weak effect of V in steel. The results from the high-temperature ductility and strength curves show that the precipitation started at 1 050 ℃ and the amount of the precipitates reach the highest within the temperature range of 900 ℃ - 50 ℃ in the condition of no deformation.

关 键 词：X70管线钢 针状铁素体 析出相 

分 类 号：TG124.11[金属学及工艺—金属学]