Stress equalization method for high temperature alloy casing ring forgings

Abstract

The invention relates to a stress uniformizing method for a high-temperature alloy casing ring forging. The circumference lengths L1 and L2 at the maximum ring diameter position and the minimum ring diameter position of the high-temperature alloy casing ring forging are measured, the yield stress sigma and required strain epsilon of high-temperature alloy are obtained through a material tensile test, and a bulging mold is manufactured according to the cross section shape and size of the high-temperature alloy casing ring forging; the high-temperature alloy casing ring forging is heated to be lower than the forging temperature and is placed in the bulging mold after soaking, a bulging cone head operates downwards by H1 and then returns after being kept for a period of time, the high-temperature alloy casing ring forging is rotated by a certain angle around the axis of the ring forging, and the bulging cone head operates downwards by H2 on the basis of H1 and is kept for a period of time, so that it is guaranteed that all positions of the high-temperature alloy casing ring forging are in the state of micro plastic deformation; and finally, the bulging cone head returns, and the high-temperature alloy casing ring forging is taken out and air-cooled to the room temperature. Uniform circumferential plastic strain is applied to the high-temperature alloy casing ring forging through the minimum deformation so as to adjust uniform distribution of residual stress.

Description

technical field [0001] The invention belongs to the field of plastic processing of high-temperature alloy casing rings, and in particular relates to a method for stress homogenization of high-temperature alloy casing ring forgings. Background technique [0002] The high-temperature alloy case ring is one of the key parts of the aero-engine, and its cross-sectional shape is complex. Usually, ring rolling or forging is used to form ring forgings with variable cross-sectional shapes, and then the casing parts are obtained by machining. Due to the uneven strain and uneven temperature during the rolling or forging process, the residual stress distribution of the casing ring forging is uneven. During the subsequent machining, the residual stress will cause serious deformation and affect the machining accuracy. During the process, the forging of the casing ring has to be stress-relieved and corrected many times before the precision machining can be continued, which makes the proces...

AI Technical Summary

Problems solved by technology

Due to the uneven strain and uneven temperature during the rolling or forging process, the residual stress distribution of the casing ring forging is uneven. During the subsequent machining, the residual stress will cause serious deformation and affect the machining accuracy. During the process, the forging of the casing ring has to be stress-relieved and corrected many times before the precision machining can be continued, which makes the processing cycle very long

[0003] In order to facilitate the smooth progress of subsequent precision machining, the currently applied methods cannot effectively remove or homogenize the residual stress in the ring forgings: the high temperature annealing stress relief method, due to the need to heat up to a higher temperature, resulting in ring forgings Forging grains have a tendency to coarsen, thereby reducing the mechanical properties of ring forgings; using vibration stress relief method, due to the solid solution strengthening and precipitation strengthening of high temperature alloys, the strength and toughness are much higher than that of general alloys, and the stress value eliminated is compared with high temperature The alloy yield strength is almost negligible, so the stress leveling effect is not good

Images