Heat treatment method for reducing nonuniformity and dimensional instability of large-size TC4 forging

Abstract

The invention relates to the technical field of hot working for performance nonuniformity and deformation of a large-size TC4 forging. According to the invention, uniform surface and center performance of a forging is ensured, and the instability problem of the forging is solved. The invention optimizes the heat treatment process, the heating temperature and the holding time are kept unchanged, and the cooling mode is changed from air cooling into furnace cooling; and the specific furnace cooling mode is that the heating temperature is reduced to 482 DEG C or below, the cooling rate is 55 DEG C / H, and then discharge and air cooling are performed.

Description

Technical field [0001] The invention relates to the technical field of thermal processing of large TC4 forgings with uneven performance and deformation. Background technique [0002] There are two types of TC4 forgings studied. One is the large TC4 forgings with a weight of more than 200Kg and an effective thickness of more than 200mm. This kind of titanium alloy is dissected and subjected to tensile test. The surface and core properties are quite different. The tensile strength of the core is much lower than the surface tensile strength. However, after this type of forging is machined, the part is the core forging, that is Say that our parts happen to use the worst part of the forging. The other is a variable forging with a length of more than 1700mm and a wall thickness of only about 30mm. [0003] The original heat treatment has the following two problems, which are difficult to solve. [0004] 1) Large long thin arm forgings are prone to deformation during the heat treatment p...