The effects of boron content (CB = 0-0.14%(mass fraction)) on the tensile properties and enviro mental embrittlement of ordered Ni-24%Fe (atom fraction)- B (Ni3Fe-B) alloys have been investigated using tensile tests i...The effects of boron content (CB = 0-0.14%(mass fraction)) on the tensile properties and enviro mental embrittlement of ordered Ni-24%Fe (atom fraction)- B (Ni3Fe-B) alloys have been investigated using tensile tests in vacuum and under gaseous hydrogen. The results indicate that, when CB < 0.06%(mass fraction), the tensile strength and elongation of the alloys in vacuum and gaseous hydrogen increase as CB in the ordered Ni3Fe-B alloy increases. The tensile strength and elongation are maximum, and the hydrogen embrittlement factor (IH) is minimum for the ordered Ni3Fe-0.06%B (mass fraction) alloy. Compared with the ordered B-free Ni3Fe alloy,IH of the ordered Ni3Fe-0.06%B (mass fraction) alloy decreases by 98.1%, and the fracture morphology of the alloy changes from fully intergranular to fully transgranular, when tested in gaseous hydrogen. A critical level of boron segregation at the grain boundaries of ordered Ni3Fe-B alloys is observed. The hydrogen embrittlement of ordered Ni3Fe- B alloys in gaseous hydrogen can be completely suppressed by boron atoms when CB ≥ 0.06%(mass fraction).展开更多
文摘The effects of boron content (CB = 0-0.14%(mass fraction)) on the tensile properties and enviro mental embrittlement of ordered Ni-24%Fe (atom fraction)- B (Ni3Fe-B) alloys have been investigated using tensile tests in vacuum and under gaseous hydrogen. The results indicate that, when CB < 0.06%(mass fraction), the tensile strength and elongation of the alloys in vacuum and gaseous hydrogen increase as CB in the ordered Ni3Fe-B alloy increases. The tensile strength and elongation are maximum, and the hydrogen embrittlement factor (IH) is minimum for the ordered Ni3Fe-0.06%B (mass fraction) alloy. Compared with the ordered B-free Ni3Fe alloy,IH of the ordered Ni3Fe-0.06%B (mass fraction) alloy decreases by 98.1%, and the fracture morphology of the alloy changes from fully intergranular to fully transgranular, when tested in gaseous hydrogen. A critical level of boron segregation at the grain boundaries of ordered Ni3Fe-B alloys is observed. The hydrogen embrittlement of ordered Ni3Fe- B alloys in gaseous hydrogen can be completely suppressed by boron atoms when CB ≥ 0.06%(mass fraction).
