一种针状铁素体钢热轧板材的结构与力学性能

Mechanical properties and microstructural characters of hot-rolled plates of an acicular ferrite steel for line pipe

在透射电镜(TEM)下观测了一种管线用针状铁素体钢热轧板材的显微组织并研究了力学性能.结果表明,这种管线用针状铁素体钢热轧板材具有较优良的强韧性能,其显微组织与焊接组织在形态上有很大的差异.管线用针状铁素体钢热轧板材中有明显界面的板条束或针状片条束;没有明显界面的板条束或针状片条束,可根据条状物或岛状物的有方向性的线状分布依稀辨别界面的存在;板条或针状片条与非等轴晶共存等多种不同形态,并不象焊接组织那样通常是单一的针状片条束或板条束形态.

Mechanical properties and microstructural characters of hot-rolled plates of acicular ferrite steel for line pipe were investigated by transmission electron micrographs (TEM). The experimental results showed that hot-rolled plates of the acicular ferrite steel for line pipe possess excellent strength and toughness behaviors. Moreover, its microstructural characters possess several configurations under TEM, which are (1) ferrite laths with obvious interface, (2) ferrite laths without obvious interface, but the interface can be discerned faintly from the linear arrangement of those directional islands, (3) the coexistence of ferrite laths and non-equiaxed grains. These are somewhat different from those of weld structures, which are generally thought to consist of an assemblage of interwoven ferrite laths.