基于FEM的INCONEL625难变形合金大型厚壁管挤压极限图研究

Extrusion Limit Map of Large-Scale Thick-Walled INCONEL625 Alloy Pipe Using FE Method

摘要:

基于DEFORM-2D有限元平台，以INCONEL625难变形合金大型厚壁挤压管为研究对象，通过虚拟正交与回归分析，研究了工艺参数坯料预热温度(P)、模具预热温度(M)、挤压速度(V)、摩擦因子(F) 、挤压比(λ)和模具几何结构参数凹模半角(β)、凹模圆角(R1,R2)、工作带长度(L)对该过程挤压力峰值和模口管材温度峰值的影响。结果表明，P，F，V，β，λ 5个参数对挤压力峰值和模口管材温度峰值的影响较为显著；通过逐步回归法建立了挤压力峰值和模口管材温度峰值与上述5个主要参数之间的回归数学模型，并通过该回归数学模型以额定挤压力200 MN和模具出口管材最高温度1250 ℃为条件确定了5个主要参数的合理取值范围：F=0.01~0.02；V=100~200 mm/s；P=1000~1250 ℃；β=35°~50°；λ=4.5~7；在此基础上，建立了多个影响显著参数下的INCONEL625难变形合金大型厚壁管挤压极限图，并阐明了该挤压极限图的制作原理和应用。经验证，该挤压极限图是可行的

Abstract:

The extrusion process for large-scale thick-walled INCONEL625 pipe was investigated by DEFORM-2D simulations. The influent significances of the process parameters including initial temperature of billet (P), initial temperature of dies (M), extrusion speed (V), friction factor (F) as well as extrusion ratio (λ) and die structure geometrical parameters angle of bottom die (β), profile radius of bottom die (R1, R2) as well as bear length (L) to the extrusion load peak (ELP) and temperature peak (TP) at the die exit of the pipe were obtained through orthogonal regression analysis. The results show that the parameters of P, F, V, β and λ have more significant influences than other parameters. The regression models of ELP and TP related to the parameters of P, F, V, β and λ are created through stepwise regression, and using the developed regression models the reasonable span of these parameters are obtained as following: F=0.01~0.02, V=100~200 mm/s, P=1000~1250 oC, β=35°~50° and λ=4.5~7. Based on the above results, the extrusion limit map has been established for the extrusion process of large-scale thick-walled INCONEL625 pipe, which can be used to fast design the feasible extrusion parameters