钒合金的氢致硬化和氢脆

  • 摘要: 通过气相渗氢后的室温拉伸试验,测试了多种钒合金材料的拉伸性能,如V4Ti、V6WlTi和V4Cr4Ti,以及日本国立核聚变研究所研制的V4Cr4Ti合金,研究了钒合金的氢脆行为及其影响因素。实验结果表明:钒合金有较强的吸氢能力,合金元素Ti能显著提高合金的吸氢量。在达到氢致脆性断裂前,氢致强化表现为典型的固溶强化,而其强化能力因Ti的存在而显著降低,是含Ti钒合金具有优良抗氢脆性能的主要原因。合金氧含量极大地影响合金的抗氢脆能力。氧含量在200~400μg/g时,V4Cr4Ti合金发生氢脆断裂的临界氢含量约为300μg/g,而当氧含量超过700μg/g时,该临界值低于50μg/g。另一方面,强度较低的V4Ti合金似乎具有更好的抗氢脆能力。

     

    Abstract: Tensile properties were measured for several vanadium base alloys with or without hydrogen charging, such as V-4Ti, V-6W-1Ti, V-4Cr-4Ti and that from the National Institute of Fusion Science in Japan. Their hydrogen embrittlement behaviors were studied. Results show that the vanadium alloys have high hydrogen absorption rate, which is increased by the Ti alloying element. Hydrogen induced hardening is found to be a solid solution one and the hardening rate could be decreased by Ti addition, which accounts for the higher resistance of the Ti-bearing alloys as compared to those without Ti. Increasing oxygen concentration would enhance the embrittlement. In that case low strength alloy showed better. The critical hydrogen concentration required to embrittle the alloy for V-4Cr-4Ti with O of 200~400 μg/g is about 300 μg/g, but lower than 50 μg/g when O content increases to 700 μg/g.

     

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