FORGED TITANIUM ALLOY MATERIAL AND METHOD FOR PRODUCING SAME, AND ULTRASONIC INSPECTION METHOD

摘要

A forged titanium alloy material having a duplex grain structure composed of flat grains and non-flat grains, wherein the flat grains are crystal grains of prior-β grains each having an aspect ratio of more than 3 and the non-flat grains are crystal grains of prior-β grains each having an aspect ratio of 1 to 3 inclusive. The forged titanium alloy material is characterized in that the average equivalent circle diameter of the non-flat grains is 100 μm or less, flat grains each having a thicknesswise diameter of 20 to 500 μm are contained in an amount of 40 to 98%, non-flat grains each having a thicknesswise diameter of 10 to 150 μm are contained in an amount of 2 to 50%, and the flat grains each having the above-mentioned thicknesswise diameter and the non-flat grains each having the above-mentioned thicknesswise diameter are contained in the total amount of 90% or more.

主权项

1. A forged titanium alloy material obtained by β forging and having a duplex grain microstructure comprising flat crystal grains that are crystal grains of prior β grains, said flat crystal grains having an aspect ratio more than 3, and non-flat crystal grains that are crystal grains of prior β grains, said non-flat crystal grains having an aspect ratio of 1 to 3,
wherein: non-flat grains having a diameter of 10 μm or more in a thickness direction thereof have an average equivalent circle diameter of 100 μm or less; flat grains having a diameter of 20 to 500 μm in a thickness direction thereof are present in a proportion of 40 to 98% relative to 100% of the flat crystal grains; non-flat grains having a diameter of 10 to 150 μm in a thickness direction thereof are present in a proportion of 2 to 50% relative to 100% of the non-flat crystal grains; and the flat crystal grains and the non-flat crystal grains are present in a total proportion of 90% or more in the forged titanium alloy.