赵晓丽. 加热温度对热成形中锰钢氢脆敏感性的影响[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2023.03.28.001
引用本文: 赵晓丽. 加热温度对热成形中锰钢氢脆敏感性的影响[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2023.03.28.001
Effect of heating temperature on the hydrogen embrittlement susceptibility in hot stamped medium-Mn steel[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2023.03.28.001
Citation: Effect of heating temperature on the hydrogen embrittlement susceptibility in hot stamped medium-Mn steel[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2023.03.28.001

加热温度对热成形中锰钢氢脆敏感性的影响

Effect of heating temperature on the hydrogen embrittlement susceptibility in hot stamped medium-Mn steel

  • 摘要: 对0.1C-5Mn中锰钢不同温度加热后进行热成形处理,利用电化学充氢及慢应变速率拉伸(SSRT)实验研究了加热温度对其氢脆敏感性的影响。结果表明,在850~1000 ℃加热后进行热成形处理,其组织全部为马氏体,且随着加热温度的升高,原奥氏体晶粒尺寸增加,而实验钢的强度和塑性逐渐降低,当加热温度为850 ℃时获得了较好的强度与塑性配合,强塑积为22 GPa?%。实验钢充氢断口起裂区均为沿着原奥氏晶界的沿晶断裂。随着加热温度升高,H含量降低而氢脆敏感性呈现先略微升高后显著降低的趋势,当加热温度为1000 ℃时,氢脆敏感性最低,氢脆断裂行为主要与热成形中锰钢的强度及ε-碳化物有关。

     

    Abstract: The medium-Mn steel with M3 characteristics (multi-phase, multi-scale, meta-stable) is a promising third-generation automotive steel due to its excellent combination of ultra-high strength and ductility. Hot stamping of the medium-Mn steel is a new process combining the steel stamping and quenching, during which the formability and mechanical properties of the steel are improved simultaneously. However, there is an increasing danger that hydrogen-induced degradation of mechanical properties with increasing steel strength grade for medium-Mn steel. For this purpose, the susceptibility to hydrogen embrittlement(HE) of a hot-stamped medium-Mn steel 0.1C-5Mn for different heating temperature were investigated by using electrochemical hydrogen charging, hydrogen permeation test and slow strain rate test (SSRT). The hot stamped specimens have martensite microstructure. When the heating temperature is 850~1000 ℃, with the increase of heating temperature, the grain size of original austenite increases, while the strength and plasticity of experimental steel decrease gradually. When the heating temperature is 850 ℃, a good combination of strength and plasticity is obtained, and the strength plastic product is 22 GPa?%. With the increase of heating temperature, the content of H decreases, while the sensitivity of HE increases slightly at first and then decreases. The H-charged specimens are fractured by intergranular cracking along the boundaries of prior grains. The difference in the original austenite grains did not influence the HE behavior, despite of the biggest grain size, the 1000 ℃ sample is relative immune to HE, suggesting that the strength and ε-carbides are detrimental to the HE resistance.

     

/

返回文章
返回