In the present study, electron backscattering diffraction (EBSD) was used to study the relationship between misorientation, grain boundary, texture, recrystallization and the mechanical properties for API (American Petroleum Institute) X90 hot induction bend. The experimental results show that the yield strength of the parent pipe is 748 MPa, while it reduced about 40 MPa after hot induction bending. The strength in the inner arc side is similar along the longitudinal and transverse direction, but it is anisotropic in the outer arc side. The texture of {113} <110> components and {112} <110> components are the main reason for anisotropy. After hot induction bending, the deformed and elongated grains exist in the bend zone of X90 bend, and the sub-grain boundaries exist in the grains. The grains in the neutral axis are equiaxed and without lath-like structure and sub-structure. A large fraction of lath bainite (LB) boundaries and Σ3 boundaries in the outer arc side resulted in a high strength and low impact toughness. Moreover, the deformed region and the recrystallization region have the same tendency for the tested specimens, the neutral axis of X90 bend has a lower stored energy in the grains that could resist the cracks propagation effectively.

在本研究中，使用电子背散射衍射（EBSD）研究了取向错误，晶界，织构，重结晶与API（美国石油学会）X90热感应弯曲的力学性能之间的关系。实验结果表明，母管的屈服强度为748 MPa，而热感应弯曲后屈服强度降低了约40 MPa。内弧侧的强度在纵向和横向上相似，但在外弧侧则是各向异性的。{113} <110>分量和{112} <110>分量的织构是各向异性的主要原因。热感应弯曲后，变形和拉长的晶粒存在于X90弯曲的弯曲区域，并且亚晶粒边界存在于晶粒中。中性轴上的晶粒是等轴的，没有板条状的结构和子结构。条状贝氏体（LB）边界和外弧侧的Σ3边界导致强度高和冲击韧性低。此外，试样的变形区和再结晶区具有相同的趋势，X90弯曲的中性轴在晶粒中的储能较低，可以有效地抵抗裂纹的扩展。