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对α+β型厚为20～76毫米并且杂质极少的TA6V(Ti-6AL-4V)和α型621Mo(Ti-6AL-2Nb-TTa-1Mo)钛合金的轧制板,进行了焊接试验和鉴定。这些合金由美国研制成功,并在海水环境中得到了应用。研究了各种不同的熔化焊接法:钨极惰性气体保护焊(TIG),金属极惰性气体保护焊(MIG),等离子焊和电子束焊(FE)。由于焊前对焊接边缘进行了适当的处理,焊时对焊接接头实施了有效地保护,不论使用那一种焊接方法均没有出现特殊的问题,焊缝的致密性令人满意。对焊接接头进行了拉伸、压缩、裂纹扩展和应力腐蚀等鉴定试验,也没有发现任何可造成严重损害的异常现象。就基板而言,TA6V合金的焊接接头,虽然延伸率和断面收缩率降低了,静态强度性能却略有提高。而621Mo合金的焊接接头,其静态强度性能则与基板相同。抗裂纹的扩展能力大体上也是好的。——对了AGV合金,K_(IC)参数值的范围是50MPam1/2(基板厚20毫米)到88MPam1/2(TIC焊接)。——对621Mo合金,K_(IC)参数值的范围是70MPam1/2(基板厚76毫米)到90MPam1/23(用等离子法焊接)。这两种合金(焊接或非焊接态),在应力腐蚀下的抗裂纹扩展能力是好的。但是,对于K_(IC)参数值,621Mo合金显然要比TA6V合金好得多。对持厚板材的焊接,最好的焊接方法看来还是电子束焊和混合焊接法(第一道缝采用等离子焊,而后用MIG焊填充焊缝)。
A welding test was performed on rolled sheets of TA6V (Ti-6AL-4V) and α-type 621Mo (Ti-6AL-2Nb-TTa-1Mo) titanium alloys having α + β type thicknesses of 20 to 76 mm and extremely few impurities And identification. These alloys were successfully developed by the United States and used in marine environments. Various different fusion welding methods have been investigated: TIG, MIG, PL, and FE. Due to the pre-welding edge of the weld has been properly handled, the welding time of the effective implementation of the welded joints, no matter whether the use of a welding method that no special problems arise, the weld density is satisfactory. Welding joints were tensile, compression, crack growth and stress corrosion identification test, also found no serious damage can cause anomalies. In terms of substrate, TA6V alloy welded joints, although the elongation and reduction of cross-sectional area, the static strength performance is slightly improved. The 621Mo alloy welded joints, the static strength properties and the same substrate. Cracking resistance is generally good as well. - For AGV alloy, K_ (IC) parameter values range from 50 MPam1 / 2 (substrate thickness 20 mm) to 88 MPam1 / 2 (TIC weld). - For 621Mo alloy, K_ (IC) parameter values range from 70MPam1 / 2 (substrate thickness 76mm) to 90MPam1 / 23 (plasma welding). Both alloys (welded or non-welded) have good crack growth resistance under stress corrosion. However, the 621Mo alloy is clearly much better than the TA6V alloy for K_ (IC) parameter values. For thick plate welding, the best welding method appears to be electron beam welding and hybrid welding (the first seam uses plasma welding followed by MIG welding).