通过电子背散射衍射(EBSD)实验,对挤压IN690高温合金管材的织构进行了研究。结果表明,孪晶与母体晶粒有着/60o的取向差关系,从而导致IN690合金挤压变形后存在较多的60°的大角晶界。IN690合金的晶界以相干孪晶晶界(Σ3)重位点阵为主体。通过比较不同挤压参数对IN690合金管材Σ3晶界比例和织构的影响,发现当挤压温度在1200℃和挤压比λ=5时,挤压管材的抗腐蚀能力和塑性较好。
The texture of the extrusion tube of super-alloy IN690 was analyzed by electron backscatter diffraction (EBSD) test. The results indicate that the orientation error between twinning and maternal grains is 〈111〉/60° for the extrusion tube of super-alloy IN690, and it results in much 60° large grain boundary after extrusion deformation. The grain boundary of IN690 is coherent twin boundary (Z3) coincidence site lattice. Comparing the X3 volume and texture in different extrusion parameters, the tube of super-alloy IN690 has excellent corrosion resistance and plasticity when the extrusion temperature is 1200 ℃ and extrusion ratio is 5.