固溶时效对新型高强耐蚀钛合金组织与性能的影响

Effect of Solution Aging Treatment on Microstructure and Properties of New High Strength Corrosion Resistant Titanium Alloy

摘要:

本文以一种新型高强耐蚀钛合金为研究对象，对钛合金热轧板材进行固溶时效热处理，研究固溶时效工艺对新型高强耐蚀钛合金板材微观组织、力学性能与腐蚀性能的影响规律。结果表明：当固溶温度由900 ℃升高至930 ℃，等轴α相和β转变组织明显增多，且皆为等轴组织形貌；当固溶温度升高至960 ℃时，等轴α相和β转变组织减少，并出现大量针状次生α相，其组织由等轴组织转变为双态组织。随固溶温度升高，板材强度和硬度增加，塑性逐渐降低，而腐蚀电流密度和腐蚀速率呈现先降低后增加的趋势。新型高强耐蚀钛合金板材900 ℃固溶30 min、580 ℃时效3h后综合力学性能最佳，其耐腐蚀性能较好。

Abstract:

In this paper, a new high-strength corrosion-resistant titanium alloy is taken as the research object, and its titanium alloy hot-rolled sheet is subjected to different solution aging heat treatments. The effects of solution aging processes on the microstructure, texture, mechanical properties and corrosion resistance of titanium alloy sheets were studied. The results show that when the solution temperature is increased from 900 ℃ to 930 ℃, the equiaxed α-phase and β-transformed structures are significantly increased, and they are all equiaxed morphologies. When the solution temperature is increased to 960 ℃, the equiaxed α-phase and β-transformed structures decrease, and a large number of needle-like secondary α-phases appear, and the structure changes from the equiaxed structure to the dual-state structure. With the increase of solution temperature, the strength and hardness of the plate increase, and the plasticity gradually decreases, while the corrosion current density and corrosion rate show a trend of decreasing first and then increasing. After the Ti603 titanium alloy plate is treated at 900 ℃ for 30 minutes and aging at 580 ℃ for 3 hours, it has the best comprehensive mechanical properties and good corrosion resistance.