钛合金中的一种富碳缺陷及其导致的变形开裂行为  

Carbon enriched defect and the associated deformation cracking behaviors in a titanium alloy

作　　者：郑友平 王立亚 秦海旭 耿乃涛 李露[3] 陈炜 ZHENG Youping;WANG Liya;QIN Haixu;GENG Naitao;LI Lu;CHEN Wei(State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization,Panzhihua 617000,Sichuan,China;Titanium Metal Technology Department of Chengdu Advanced Metal Materials Industrial Technology Research Institute Co.,Ltd.,Chengdu 610399,Sichuan China;Pangang Group Jiangyou Changcheng Special Steel Co.,Ltd.,Jiangyou 621704,Sichuan,China)

机构地区：[1]钒钛资源综合利用国家重点实验室,四川攀枝花617000 [2]成都先进金属材料产业技术研究院股份有限公司,四川成都610399 [3]攀钢集团江油长城特殊钢有限公司,四川江油621704

出　　处：《钢铁钒钛》2025年第1期45-52,共8页Iron Steel Vanadium Titanium

基　　金：国铁集团重点课题(N2023J049);国家重点研发计划项目(2023YFB3710700)。

摘　　要：针对Ti-6Al-4V钛合金锻棒中超声波探伤出现异常杂波的问题,通过光学显微镜和扫描电镜金相分析、显微硬度、能谱、电子探针、背散射电子衍射等表征方法,在锻棒中出现异常杂波的位置发现了不常见的富碳缺陷及其导致的裂纹缺陷。首先,在微观组织中观察到了一种被α相稳定区域环绕的斑块特征。然后,通过化学成分和晶体学分析,确认了这种斑块是具有有序FCC晶格的Ti_(2)C相,而环绕的α相稳定区域则是由硬α相组成。根据化学元素分布特点,推定缺陷来源是受到富含碳氮等元素的异物污染的原材料。在锻造变形过程中,微裂纹在Ti_(2)C/α相界形成,并向α相内扩展。微裂纹最终突破Ti_(2)C晶粒的裂尖桥接作用,汇合形成宏观裂纹缺陷。Since the contacting ultrasonic detection results indicated some defects existed in a bar of Ti-6Al-4V alloy,researching work had been carried out using optical microscope,scanning electron microscope metallographic analysis,microhardness,energy spectrum,electron probe,backscatter electron diffraction and other characterization methods.And uncommon carbon enriched defect had been figured out.Flecks surrounded withαstable area were observed in the microstructure.Then,it was figured out that flecks were Ti_(2)C with ordered FCC crystal and theαstable area was hardαphase based on the chemical composition and crystallology analysis.According to the distribution characteristics of chemical elements,the defect source was presumed to be raw materials contaminated by elements rich in carbon and nitrogen.Micro cracks initiated at Ti_(2)C/αboundaries and grew into theαside in the hardαand Ti_(2)C regions during the forging.Micro cracks would break through the Ti_(2)C crystal bridges and merged into ultrasonically detectable macro crack defects at last.

关 键 词：富碳缺陷 硬α相 Ti_(2)C 裂尖桥接 

分 类 号：TF823[冶金工程—有色金属冶金]