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采用金相(OM)、电子背散射衍射(EBSD)以及拉伸实验等技术手段研究了不同变形量条件下Hastelloy C-276合金薄板的组织演化特征和力学性能。结果表明:变形量小于14%时,位错优先在晶界附近塞积,并产生局部应变集中;变形量在14%~30%范围内,孪晶界附近及晶粒内部产生大量位错,位错滑移引起晶粒内部应变集中增强;变形量由0%增加至30%,晶界应变集中程度因子先增大后减小,变形量为14%时晶界应变集中程度因子最大。利用Ludwigson模型回归拟合了不同变形条件下的真应力-真应变曲线,随变形量的增加,材料的加工硬化程度提高,加工硬化速率减小,发生单滑移向多滑移转变的临界应变减小。
The microstructure evolution and mechanical properties of Hastelloy C-276 alloy sheet under different deformations were studied by OM, EBSD and tensile test. The results show that dislocation preferentially piles up around the grain boundary and causes local strain concentration when the deformation is less than 14%. A large number of dislocations are generated in the vicinity of the twin boundary and in the grain within the range of 14% ~ 30% The dislocation slip caused the concentration of strain in the grain boundaries to increase intensively. The amount of deformation increased from 0% to 30%. The strain concentration in the grain boundary first increased and then decreased, and the strain concentration was 14%. The true stress-strain curves under different deformation conditions were fitted by Ludwigson model regression. With the increase of deformation, the degree of work hardening increased, the work hardening rate decreased, and the critical strain of single slip to multi-slip transition occurred Decrease