Ti6242 wear-resistant plate alloy is a near-α alloy, and its domestic brand is TA19. Because of its good high-temperature properties, it can be used in aerospace engine compressor components and aircraft skin materials. The nominal composition of Ti6242 wear-resistant plate alloy is Ti-6A1-2Sn-4Zr-2Mo, in which the added aluminum is an effective α-stabilizing element; the added molybdenum is a strong β-stabilizing element with a medium content; and the added tin and zirconium are solid The solution-strengthening elements have a neutral stabilizing effect on the phase; the combined effect of these alloying elements is to produce a weakly β-stable α+β alloy. Since the alloy is a weakly β-stable alloy, the alloy is nearly α-type. α+β alloy.
The researchers studied the room temperature tensile properties and structure of Ti6242 wear-resistant plate alloy after solution aging treatment at different temperatures. The purpose was to study the relationship between the structure and tensile properties of Ti6242 wear-resistant plate alloy at different solution temperatures. It aims to optimize the heat treatment system of Ti6242 wear-resistant plate alloy and provide a theoretical basis for heat treatment in actual industrial production.
The material used in the experiment is a Φ460mm TA19 ingot prepared by vacuum consumable arc melting. The phase transition point of the alloy was measured to be 991°C using differential thermal analysis. The ingot is blasted with three fires in the β phase zone, forged to Φ100mm, and rolled into Φ16mm bars through the α+β two-phase zone. The rolled structure in the two-phase zone is α+β processed structure. The heat treatment system used in the experimental alloy is water cooling at different temperatures (910, 940, 970, 985, 1000, 1015 and 1030°C) and 1 hour of water cooling + 8 hours of air cooling at 600°C. The tensile test uses an Instron tensile machine, and the OLYMPUSPMG3 inverted microscope and JSM-6760 scanning electron microscope are used to observe the microstructure of the material. The photos taken were image processed using Photoshop6.0 to achieve the peeling off of the equiaxial α phase and striped α phase. After completion, Image-Pro-Plus6.0 image processing software was used to realize the peeling of the equiaxial α and striped α phases. Size statistics.
The results showed that:
(1) When the solid solution temperature is 910~985°C, as the solid solution temperature increases, the increase in the equiaxed α size and lamellar thickness weakens the contribution of the increase in strip α to strength, resulting in tensile strength and yield strength. Decrease, plastic indicators such as elongation and area shrinkage change less.
(2) When the solid solution temperature is 1000°C, the increase in strip α size causes a decrease in tensile strength and yield strength; the equiaxed α content decreases significantly (5% to 6%), the deformation coordination ability of the structure decreases, and the plasticity decreases. , the elongation is reduced by 3%, and the area shrinkage is reduced by 16%.
(3) Widmansite structure is obtained during solid solution treatment at 15~30℃ above the phase transformation point, which is manifested by a sharp decrease in strength and plasticity. The area shrinkage is only 14%~15%, the strength decreases significantly, and the yield strength is about is 900MPa, and the tensile strength is about 1060MPa; as the temperature increases, the length of the sheet α decreases and the width increases at 1030°C, and the material properties rebound.
