ABSTRACT

The current research introduces a low-cost strategy to improve strength-ductility-toughness balance in low-carbon steel containing 0.08 wt-% carbon by simple heat treatment. As the intercritical annealing temperature increased, the fraction of martensite enhanced. By increasing the annealing temperature from 770 to 830°C, the hardness of dual-phase steel was increased from 183 HV to 212 HV, which was due to the increment of martensite fraction from 0.28 to 0.49. The strength of all dual-phase steel samples produced by intercritical annealing treatment was higher than that of the initial sample owing to the presence of hard martensite in the soft ferrite. The interesting point was that the ductility of the dual-phase steels was almost the same as the initial sample. This led to a remarkable increase in the toughness of dual-phase steels compared to the initial sample. All dual-phase steels revealed a perfect ductile fracture.

摘要

目前的研究引入了一种低成本策略，通过简单的热处理来改善含碳 0.08 wt% 的低碳钢的强度-延展性-韧性平衡。随着相间退火温度的升高，马氏体的分数增加。通过将退火温度从770℃提高到830℃，双相钢的硬度从183HV提高到212HV，这是由于马氏体分数从0.28增加到0.49。由于软铁素体中存在硬马氏体，通过相间退火处理生产的所有双相钢样品的强度均高于初始样品的强度。有趣的是，双相钢的延展性几乎与初始样品相同。与初始样品相比，这导致双相钢的韧性显着增加。所有双相钢均表现出完美的延性断裂。