TWIP钢的组织与力学性能研究

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF TWIP STEELS

采用金相、静态拉伸试验方法研究了5种不同锰含量的TWIP钢的组织和力学性能。结果表明,5种钢的屈服强度随应变率的增大而提高,最大屈服强度可达280MPa;抗拉强度随应变率的增大而略有降低,最高抗拉强度超过1000MPa;1#钢的断裂延伸率和强塑积随应变率的增大而提高,其它4种成分钢的断裂延伸率和强塑积随应变率的增大而减小。1#钢只具形变诱发马氏体相变,不出现孪晶;而2#-5#钢具TWIP效应,其中3#钢的最大延伸率可达75%,强塑积最高可达45000MPa（%）。TWIP钢拉伸前组织中有退火孪晶,变形过程中产生大量的形变孪晶,孪晶诱导塑性,从而推迟了颈缩的产生,导致很高的均匀变形能力。

Microstructure and mechanical properties of five different Mn content steels were studied by static tensile test and metallography examination. The results showed that yield strength increased with increasing strain rate but tensile strength was opposite. Maximum yield strength could reach up to 280MPa and maximum tensile strength was more than 1000MPa. Total elongation and product of strength and ductility of 1 # steel increased with increasing strain rates but others did reversely. 1 # steel had no twins and only appeared deformation induced martensite transformation, but 2 # - 5 # steel had TWIP effect. Maximum total elongation could reach up to 75 % and maximum product of strength and ductility could attain 45000MPa （%）. Many annealing twins appeared before tension. A lot of deformation twins appeared during deformation, twinning induced plasticity, so the necking was delayed and the ability of uniform deformation was obtained.