合金成分对锆合金焊接区腐蚀时吸氢性能的影响

采用Fe含量相同，但Cr含量不同的锆合金板与Zr-4板对接焊，腐蚀后不同样品中的氢含量差别很在，与氧化膜的厚度不成比例，说明合金元素Cr对锆合金的吸氢性能有着非常明显的影响，当不含Cr时，焊接样品腐蚀后的氢含量明显减少：Zr．4经不同热处理后Zr(Fe，Cr)2第二相的大小和多少与氢含量有关，说明合金中存在Cr时形成的Zr(Fe，Cr)2第二相是引起吸氢量增加的主要原因。在不含Cr的锆合金中添加合金元素Nb，不仅改善了焊接区的耐腐蚀性能，而且不会引起腐蚀时吸氢增加。氯化锆会在对接焊样品中未焊透的前端析出，这是张应力引起氢的扩散富集并诱发氢化物析出的结果。氢化锆还会沿着熔区边界集中析出，这将影响锆合金力学性能的均匀性。

The Effect of Alloying Composition on Hydrogen Uptake of Welding Zones of Zirconium Alloys during Corrosion Tests

When the zirconium alloy plates with the same Fe content and different Cr content were used to make the butt joints with Zr-4 alloy plates, the hydrogen content in welding samples is obviously different after corrosion and is not in proportion to the thickness of oxide films. This shows that alloying element Cr has a significant effect on hydrogen uptake performance. The hydrogen content in welding samples, in which zirconium alloy plates being used to make the butt joints with Zr-4 plates dont contain Cr, decreases sharply after corrosion. The relationship between hydrogen content and the number and size of Zr(Fe,Cr)2 second phase particles in Zr-4 with different heat-treated states indicates that the formation of Zr(Fe,Cr)2 second phase particles is the main reason that the amount of hydrogen uptake increases. Adding Nb alloying element in zirconium alloys without Cr, not only improves the corrosion resistance, but also make hydrogen uptake not to increase. The zirconium hydrides induced by tensile stress are easy to precipitate in the front of faulty fusion, and they are also easy to precipitate along the interface between molten zones and matrix. These will influence the dispersity of mechanical properties.