Method for preventing deformation cracking of laser deposition formed A-100 steel structure

Abstract

The invention relates to the technical field of aeronautical manufacturing, and in particular, provides a method for preventing deformation cracking of a laser deposition formed A-100 steel structure. The method comprises the following steps: (1) in the forming process of laser deposition formation of A-100 steel, each layer of laser deposition formed section is peripherally and uniformly zoned in the laser deposition forming growth direction; at least six subareas are provided; the laser scanning filling is performed on each subarea of the section according to a discrete forming mode; filling rules of each subarea are as follows: two adjacent subareas are not near on the filling sequence; and a filling path when filling any subarea is S-shaped; and (2) the stress relief annealing is performed on a part after formation within 24 h, and comprises the procedures of heating of the part to 190-450 DEG C for lasting by 2-4 h and air cooling or oil cooling to the room temperature. The method can effectively reduce generation of the heat stress of overall structure of the laser direct deposition formed A-100 steel.

Description

technical field [0001] The invention relates to the technical field of aviation manufacturing, in particular to a method for preventing deformation and cracking of A-100 steel structures formed by laser deposition. Background technique [0002] Laser direct deposition forming is a kind of additive manufacturing technology. It is the first in the world to use laser direct deposition forming A-100 steel to manufacture integral structural parts. During the forming and solidification process of A-100 steel laser direct deposition forming structural parts, the temperature gradient in the forming material is large, and the thermal expansion coefficient of A-100 steel is large, and the cooling shrinkage is large, which is very easy to generate thermal stress and induce structural deformation or surface cracking. Especially for parts with larger forming sections, the cracking tendency increases. Therefore, how to control the deformation and cracking of structural parts formed by las...

AI Technical Summary

Problems solved by technology

During the forming and solidification process of A-100 steel laser direct deposition forming structural parts, the temperature gradient in the forming material is large, and the thermal expansion coefficient of A-100 steel is large, and the cooling shrinkage is large, which is very easy to generate thermal stress and induce structural deformation or surface cracking. Especially for parts with large forming cross-sections, the cracking tendency increases. Therefore, how to control the deformation and cracking of structural parts formed by laser direct deposition of A-100 steel has become the key to the application of this technology.

At present, there is no practical method to control the deformation and cracking of the overall structure of A-100 steel laser direct deposition forming in China.

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