热处理工艺对TiB95合金石油管材微观组织与力学性能的影响

Effect of Heat Treatment on Microstructure and Mechanical Properties of TiB95 Alloy Petroleum Pipes

为满足苛刻油、气开采环境下对钛合金油井管的需求,开发了TiB95合金,该合金为Al-Mo-Zr系合金。采用金相显微镜、拉伸试验机、冲击试验机和扫描电镜等研究了不同热处理工艺的TiB95合金管材的金相组织、力学性能和冲击断口形貌。研究结果表明:TiB95合金管材在相同热处理温度下(900℃),冷却速率较慢(炉冷)时组织较粗大,强度较低,韧性较高;在相同冷却速率下(空冷),热处理温度较高时(960℃),α相形态发生改变,强度降低,伸长率升高,韧性显著提高。TiB95合金管材采用960℃、90 min、空冷热处理工艺处理时,可以获得较高的强韧性匹配。TiB95合金管材不同热处理工艺下的冲击断口形貌均为韧窝,为韧性断裂。

In order to meet the demand for titanium alloy petroleum pipes under the harsh oil and gas exploitation environment,the TiB95 alloy is developed,which belongs to Al-Mo-Zr alloys.The effects of different heat treatment processes on the metallographic structure,mechanical properties and impact fracture morphologies of the TiB95 alloy petroleum pipes are studied by means of metallographic microscope,tensile testing machine,impact testing machine and scanning electron microscope.The results show that when the heat treatment temperature is 900 ℃,the TiB95 alloy petroleum pipes cooled at low rate(furnace cooling) have coarser structure,lower strength and higher toughness.When the cooling rate(air cooling) is the same,the α phase morphologies of the TiB95 alloy petroleum pipes heat treated at high temperature changes,the strength of the alloy reduces,and the elongation increases.The TiB95 alloy petroleum pipes with high strength and toughness can be obtained by using the 960 ℃,90 min,air cooling heat treatment process.The impact fracture surfaces of the TiB95 alloy petroleum pipes by different heat treatment processes are dimple morphology,which is ductile fracture.