影响TC4合金大规格锻棒表面质量和力学性能因素分析及工艺改进

针对TC4合金大规格锻棒生产表面出现大量裂纹,且力学性能不能达到国标要求的问题,分析了影响锻棒表面质量和力学性能的主要因素,提出了通过制定合理的加热工艺并尽量采用电加热炉加热、控制合金的终锻温度≥780℃及控制合金初锻单边压下量≤25 mm来提高棒材的表面质量；通过控制合金的配料为Al 6.4％左右、V4.2％左右、00.1％左右,方坯加热温度在相变点以下10℃至相变点以上5℃,方坯到棒材的变形量在30％以上来改善锻棒的力学性能.采取这些措施后,生产出的大规格TC4合金锻棒表面质量得到了较大改善,且力学性能可达到国标要求.

Analysis on Surface Quality and Mechanical Properties for Large Size TC4 Alloy Bars and Process Improvement

Aiming at the problem that the cracks were easily appeared on the surface of TC4 alloy forging bars and mechanical properties were usually hard to reach the Chinese standard requirements,the main influence factors were analyzed,and the improved measures were proposed.The surface quality can be improved by adopting proper heating process and using electric heating furnace,controlling the final deformation temperature≥780 ℃ and the initial forging unilateral reduction≤25 mm.Besides,the mechanical property can also be improved by controlling the chemical composition of alloy as Al 6.4%,V 4.2%,O 0.1%,the heating temperature for the square billet between 10 ℃ under the phase transformation points and 5 ℃ above it,and the finally deformation degree above 30%.The result shows that the surface quality of TC4 alloy forging bar has been greatly improved and its mechanical properties can totally meet the Chinese standard requirements by the implementation of the above measures.