含铁素体/珠光体带状组织管线钢热变形行为研究

Research on Thermal Deformation Behavior of Pipeline Steel with Ferrite/Pearlite Banded Structure

由于成分偏析而形成的铁素体/珠光体带状组织会引起高强度管线钢力学性能的各向异性。通过热变形试验探究铁素体/珠光体带状组织对X80钢级管线钢热变形行为的影响。试验结果表明:相比于铁素体带,珠光体带存在明显应变集中,但X80钢级管线钢在轧制方向和横向的热膨胀系数差异很小,即带状组织虽然影响微观热变形的分布,但是对高强度低合金管线钢的热膨胀系数影响很小。

The ferrite/pearlite banded structure as formed due to component segregation shall cause anisotropy of the mechanical properties of the high-strength pipeline steel.The effects by the ferrite/pearlite banded structure on the thennal deformation behavior of the X80 pipeline steel are investigated by means of the thermal deformation test.As a result it is identified that compared with the ferrite band,the pearlite band stays with obvious stress concentration;whereas the difference between the rolling directional thermal expansion coefficient and the transversal thennal expansion coefficient is so little,which means that although the banded structure affects the distribution of the micro-thennal deformation,it so slightly affects the thermal expansion coefficient of the high-strength,low alloy X80 steel.