低成本X70管线钢力学性能的各向异性研究

Investigation on Mechanical Property Anisotropy of Low Cost X70 Pipeline Steel

对低成本X70管线钢的拉伸性能、冲击韧性和全尺寸落锤韧性的各向异性进行了研究。发现,屈服强度和抗拉强度检测结果呈现横向>纵向>斜向规律,其中30°方向检测结果最低。屈服强度和抗拉强度随取样方向的不同,变化范围在85 MPa和95 MPa内。冲击韧性的各向异性不明显,到-60℃各个方向试样均未发生脆性断裂。全尺寸落锤韧性的各向异性也不明显,-60℃各个方向剪切面积均大于85%,断面形貌仍为解理面。

This article analyzed the mechanical property anisotropy of low cost X70 pipeline steel,focused on tensile property,impact and drop weight tear test toughness.The result showed that the anisotropy of yield strength and tensile strength fellow the rules:specimen from transverse direction>specimen from rolling direction>angled specimen.The minimum value was found in the 30°angle of rolled direction.The range of yield strength was 85 MPa varies from sample direction.The range of Tensile strength was 95 MPa varies from sample direction.Anisotropy was not found in impact and DWTT toughnes.There is no brittle fracture happened at-60℃.The shear area of DWTT samples from any direction tested at-60℃is bigger than 85%,the fracture morphology was the accurate cleavage fracture.