New guideline is required in forming high strength steel line pipes since spring back is quite higher than that of the conventional materials. Moreover,line pipes have plastic anisotropy,which the work hardening coefficients are different between the longitudinal and the circumferential direction,caused by the forming strain and the strain aging during the heating in anti-corrosion coating. However,the effect of the plastic anisotropy on the pipe performance has not been clarified. This paper describes the numerical simulation models of the UOE pipe forming and the pipe bending with two different yield functions,which are capable of representing the plastic hysteresis and the orthogonal anisotropy respectively. The forming models introduce the operating guidelines corresponding to the material strength and the design indexes of the apparatus to aid the lack of the press capacity. The bending models reveal that yield point elongation on stress vs. strain curve in the circumferential direction in addition to the longitudinal direction degrades the buckling resistance and the decreasing rate is dependent on size and internal pressure.%UOE钢管成型应变和防腐涂层加热时的应变时效造成管线钢管的塑性具有各向异性,并且钢管纵向和周向的加工硬化系数不同。但是,塑性各向异性对于钢管工艺性能的影响目前尚未有明确的定论。采用两个能够分别代表塑性滞后和正交各向异性的不同屈服函数,建立了UOE钢管成型和弯曲的数学仿真模型。研究表明,成型模型引入了与材料强度和装备设计指标相对应的操作方案可以弥补下压能力的欠缺;弯曲模型说明应力-应变曲线上屈服点的伸长降低了钢管周向与纵向的屈曲极限,其降低程度取决于钢管的规格和内压。
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