The straightening difficulty of high-strength alloy materials (such as titanium alloy TC4, high-temperature alloy GH4169) and slender shaft workpieces (aspect ratio>20) is relatively high, and targeted adjustments and modifications need to be made from both the process and equipment aspects to ensure that the workpiece has no cracks and uniform deformation after straightening. In terms of process adjustment: firstly, the segmented straightening process is adopted, dividing the workpiece into 3-5 sections and gradually straightening them from the middle to both ends. After each section is straightened, it stays for 5-10 seconds (the holding time is adjusted according to the material, and the high-temperature alloy needs to be extended to 15 seconds), to avoid applying excessive pressure at once and causing the workpiece to break; The second is to control the straightening temperature. For alloy materials with a yield strength exceeding 1000MPa, heating straightening (using an induction heating device to locally heat the workpiece to 200-300 ℃, below the material's phase transition temperature Ac1) is required to reduce the material's yield strength and straightening force (which can be reduced by 30% -40%); The third is to optimize the pressing amount, adopting the principle of "small increment multiple adjustments", with each pressing amount controlled at 0.1-0.3mm (0.5-1mm for ordinary steel parts), and real-time detection of bending changes through laser to avoid excessive straightening.

The equipment renovation needs to focus on three core aspects: firstly, enhancing the straightening force output, upgrading the conventional hydraulic system to a servo hydraulic system (increasing the working pressure from 25MPa to 31.5MPa), and replacing the high-strength main column (using 40CrNiMoA alloy steel integral forging, with a tensile strength of ≥ 1080MPa); The second is to optimize the workpiece support. For slender shaft workpieces, movable auxiliary support rollers (the support spacing can be adjusted by servo motors, with an accuracy of ± 0.5mm) are installed. The surface of the support rollers is wrapped with polyurethane material (hardness Shore 85A) to prevent scratches on the workpiece surface; The third is to upgrade the detection system, using 3D laser scanning detection (scanning speed ≥ 500 points/second) to comprehensively capture the spatial bending shape of the workpiece, avoiding the distortion and deformation missed by traditional 2D detection; The fourth is to increase the stress relief function by adding a vibration aging device (vibration frequency 20-100Hz, amplitude 0.1-0.5mm) after the straightening station to eliminate residual stress generated during the straightening process (residual stress should be controlled below 150MPa) and prevent subsequent deformation of the workpiece.

A certain aerospace parts factory straightened titanium alloy slender shafts (diameter 20mm, length 500mm). After the above transformation, the straightening qualification rate increased from 75% to 98%, and the residual stress of the workpiece met the requirements of AMS 2632 standard. After the transformation, attention should be paid to real-time temperature monitoring (using an infrared thermometer with an accuracy of ± 2 ℃) during heating and straightening to avoid material performance degradation caused by excessive temperature; The auxiliary support roller needs to be regularly inspected for wear, and the polyurethane surface should be replaced every 500 workpieces straightened