对各类钛合金的晶粒度评定做了定义。应用GB/T 6394-2017中的比较法和截点法对α，β类钛合金材料的晶粒度进行了评定。对α-β两相合金中出现的等轴组织、双态组织、网篮组织、魏氏组织、非等轴组织及特殊组织的晶粒度评定方法做了应用研究。结果表明：α，β类单相钛合金、各相含量明确的α-β两相钛合金及再结晶热处理后的超细晶组织，均可应用GB/T 6394-2017中比较法和截点法来进行晶粒度评定。

The determination of grain size for various titanium alloys was defined. The grain size of α,β titanium alloys was determined by the comparison method and intercept procedure in GB/T 6394-2017. The methods of grain size determination for equiaxed microstructure, duplex microstructure, basketweave microstructure, widmanstatten, non-equiaxed microstructure and ultrafine grain microstructure in α-β two-phase titanium alloys were studied. The results show that comparison method and intercept procedure in GB/T 6394-2017 can be used to determine the grain size of α and β single-phase titanium alloy, α-β two-phase titanium alloy with definite phase content and ultrafine grain microstructure after recrystallization heat treatment.