Abstract Advanced high strength steels (AHSS) have high susceptibility to hydrogen embrittlement, and are often exposed to hydrogen environments in processing. In order to study the embrittlement and recovery of steel, tensile tests were conducted on two different types of AHSS over time after hydrogen charging. Concentration measurements and hydrogen microprinting were carried out at the same time steps to visualize the hydrogen behavior during recovery. The diffusible hydrogen concentration was found to decay exponentially, and empirical relations were found for both types of steel. Hydrogen concentration decay rates were determined to be -0.355 /hr in TBF-980, and -0.225 /hr in DP-980. Hydrogen concentration thresholds for embrittlement were found to be 1.04 mL/100 g for TBF, and 0.87 mL/100 g for DP steel. TBF steel is predicted to recover from embrittlement within 4.2 h, compared to 7.2 h in DP steel. A two-factor method of evaluating recovery from embrittlement, requiring hydrogen concentration threshold and decay rate, is explained for use in predicting recovery after exposure to hydrogen. Anisotropic hydrogen diffusion rates were also observed on the surface of both steels for a short time after charging, as hydrogen left the surface through and grains faster than grains with orientations. This could be explained by differences in surface energies between the different orientations.

中文翻译：

---

先进高强钢氢脆及连续恢复的显微组织评价

摘要 先进高强度钢（AHSS）对氢脆的敏感性高，加工过程中经常暴露在氢环境中。为了研究钢的脆化和恢复，在充氢后随时间对两种不同类型的 AHSS 进行了拉伸试验。浓度测量和氢显微打印同时进行，以可视化恢复过程中的氢行为。发现扩散氢浓度呈指数衰减，并发现两种钢的经验关系。氢浓度衰减率在 TBF-980 中确定为 -0.355/hr，在 DP-980 中为 -0.225/hr。发现脆化的氢浓度阈值对于 TBF 为 1.04 mL/100 g，对于 DP 钢为 0.87 mL/100 g。预计 TBF 钢可在 4.2 小时内从脆化中恢复，而 DP 钢则为 7.2 小时。解释了评估脆化恢复的两因素方法，需要氢浓度阈值和衰减率，用于预测暴露于氢后的恢复。在充电后的短时间内，在两种钢的表面上也观察到了各向异性的氢扩散速率，因为氢离开表面的速度比有取向的晶粒更快。这可以通过不同取向之间的表面能差异来解释。在充电后的短时间内，在两种钢的表面上也观察到了各向异性的氢扩散速率，因为氢离开表面的速度比有取向的晶粒更快。这可以通过不同取向之间的表面能差异来解释。在充电后的短时间内，在两种钢的表面上也观察到了各向异性的氢扩散速率，因为氢离开表面的速度比有取向的晶粒更快。这可以通过不同取向之间的表面能差异来解释。