采用单向拉伸、金相组织观察、TEM等方法，研究了3种不同碳含量Fe-Ni-Mn-Si-C系TWIP钢的拉伸应变硬化行为。研究结果表明，随着碳含量的增加，合金的强度和伸长率均提高，当碳质量分数为1.0%时，该TWIP钢具有较好的综合力学性能，强塑积达到83160MPa·%。3种TWIP钢的真应力-真应变曲线均不完全遵循Hollomon的线性关系。在低应变阶段，碳含量高的合金应变硬化指数略低于碳含量低的合金。而在高应变阶段，n值随碳含量的增加而增大并维持于一定值。该类TWIP钢的微观变形机制是: 当真应变ε<0.12时，位错滑移为主要的变形机制；当0.12<ε<0.42时，强化机制以应变诱发孪晶为主。碳含量的增加，推迟了形变孪晶的产生，延长了应变硬化行为的第2阶段，提高了合金的强度与韧性。
The strain hardening behavior of three Fe-Ni-Mn-Si-C TWIP steels with different carbon content were investigated by uniaxial tensile tests, metallography and TEM. The results show that the strength and elongation of TWIP steels are enhanced with the increasing of the carbon content. TWIP steel has batter comprehensive properties when the carbon content is 1.0%, and the strength-plasticity product is 83160MPa·%. The Hollomon relationship is inapplicable. At lower true strain stage, the value of n decreases with the higher carbon steel,and at higher true strain stage, the value of n increases with the increasing of the carbon content and maintains a fixed value. The micro mechanisms are: when the value of strain is lower than 0.12, dislocation slipping is the predominant mode, deformation twin production is the main mode when the value of strain is between 0.12 to 0.42. Deformation twins would be putted off with the increasing of the carbon content, and prolonged stageⅡof the strain hardening behavior, enhanced the strength and ductility of the alloy.
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