Equiaxed crystal material turbine guide vane casting defect repair material and repair method

Abstract

The invention relates to the technical field of repairing key parts of the hot end of an aero-engine, and provides a repairing material for casting defects of an equiaxed crystal material turbine guide vane and a repairing method. And mass percentage: C: 0.12~0.18%, Cr: 15.5~16.5%, Co: 12.5~13.5%, W: 3.5~4.5%, Mo: 3.5~4.5%, Nb: 0.6~1.0%, Al: 2.0~ 2.5%, Ti: 3.5-4.0%, Zr: 0.03-0.08%, B: 0.006-0.015%, Ta: <0.2%, Si: <0.2%, Mn: <0.12%, Fe: <0.35%, P: ≤0.01%, S: ≤0.01%, O: ≤0.010%, N: ≤0.008%, Ni is the balance; the repair method is to carry out solid solution heat treatment on the blade to be repaired before the repair: and then use the laser direct deposition method to repair , and restore the size; the repair method and repair material of the present invention have achieved a substantial improvement in the repair efficiency, repair joint quality and performance of high Al, Ti content equiaxed crystal superalloy turbine guide vanes, which is of great significance to promote the development and application of engines .

Description

technical field [0001] The invention relates to the technical field of repair, in particular to a repairing material and a repairing method for a casting defect of a turbine guide vane made of an equiaxed crystal material. Background technique [0002] In view of the high performance requirements of advanced aero-engines, equiaxed superalloys with high Al and Ti content are more and more widely used in engine turbine guide vanes, such as K418B, K447A and K465. In order to improve the cooling effect of aero-engine turbine guide vanes, domestic and foreign turbine guide vanes generally adopt a multi-connected air-cooled hollow structure. The inner cavity is complex, the blade body wall and edge plate are thin, and the dimensional accuracy is high, which makes the casting process of the blade difficult. Large, resulting in local defects such as shrinkage cavities, shrinkage porosity, voids, under-casting, and inclusions in casting products, making it unable to meet the use requ...

AI Technical Summary

Problems solved by technology

In order to improve the cooling effect of aero-engine turbine guide vanes, domestic and foreign turbine guide vanes generally adopt a multi-connected air-cooled hollow structure. The inner cavity is complex, the blade body wall and edge plate are thin, and the dimensional accuracy is high, which makes the casting process of the blade difficult. Large, resulting in local defects such as shrinkage cavities, shrinkage porosity, voids, under-casting, inclusions and other local defects in casting products, making it unable to meet the use requirements, and the scrap rate of new castings is often as high as 70%, so it is urgent to repair

[0003] Because the “Al+Ti” content in equiaxed superalloys with high Al and Ti content is as high as 6.2-8.9wt.%, the joints (including the repaired area and the thermal Influenced area) is very prone to thermal cracks, and often needs to be repaired more than twice, which leads to extremely unstable repair quality on the one hand, and on the other hand, the qualified rate of repair is usually less than 30%

The low content of Al and Ti makes the repair material have excellent formability (that is, weldability), but it also makes it difficult to precipitate age-strengthened γ′-strengthened in the repaired area. 3 Al phase, resulting in a significant decline in the room temperature strength, durability and temperature resistance of the repaired area

This has led to the casting defect repair area of ​​equiaxed crystal superalloy turbine guide blades becoming a "short board" when the parts are in service, which seriously affects the service life and reliability. Material