Abstract: According to the problem of large extrusion deformation of Inconel690 nickel-based superalloy, the solving process of element-free Galerkin method(EFG) in cylindrical coordinates and the software program is prepared, the Inconel690 alloy flow stress constitutive relation model is established with adopting Gleeble-1500 thermal simulation experiment machine, and the Inconel690 nickel-base superalloy tube extrusion deformation behavior is also simulated. The EFG method is established with using penalty function imposed on essential boundary conditions, computing boundary friction with arctangent friction model adopted and solving stiffness equation using Newton-Raphson iterative method. Extrusion pressure compared with measured values error within 7%. In the deformation zone randomly selected several nodes, the results are compared with the DEFORM calculations, the maximum error is within 8%, the correctness of meshless EFG and the software is demonstrated. The calculated results show the steady extrusion pressure, velocity field, equivalent strain rate field and equivalent stress field. The plastic deformation zone deformation behavior of metals with the calculated results is analyzed. And based on the EFG method and the software established in this paper which improves optimize efficiency, the minimum extrusion pressure of nickel-based superalloy hot extrusion deformation process as the optimization goal, Inconel690 nickel-base superalloy tube hot extrusion process parameters with orthogonal experimental design simulation conditions is optimized.

Key words: Inconel690 alloy;extrusion;element-free Galerkin method;process optimization