Manufacturing method of forged products of near β-type titanium alloy

摘要

This invention relates to nonferrous metallurgy, namely to thermomechanical processing of titanium alloys and can be used for manufacturing structural parts and assemblies of high-strength pseudo-²-titanium alloys in aerospace engineering, mainly for landing gear and airframe application. The method for thermomechanical processing of titanium alloy items consisting of, in weight percentages, 4.0 - 6.0 aluminum, 4.5 - 6.0 vanadium, 4.5 - 6.0 molybdenum, 2.0 - 3.6 chromium, 0.2 - 0.5 iron, 2.0 max. zirconium, 0.2 max. oxygen and 0.05 max. nitrogen is proposed. The method consists of multiple heating operations to a temperature that is above or below beta transus temperature (BTT), hot working with the specified strain and cooling. A technical result of this method is manufacture of near-net shape forgings with stable properties having sections with thickness 100 mm and over and length over 6 m with the guaranteed level of the following mechanical properties: 1. Ultimate tensile strength over 1200 MPa with fracture toughness, K 1C , not less than 35MPaˆšm. 2. Fracture toughness, K 1C , over 70 MPaˆšm with ultimate tensile strength not less than 1100 MPa.