Twins and Texture of Super-Alloy IN690 Tube by Extrusion

Abstract:

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 (Σ3) coincidence site lattice. Comparing the Σ3 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 oC and extrusion ratio is 5

Key words:super-alloy; IN690; extrusion; tube; twinning; texture