摘要
在搅拌摩擦焊接钢铁材料时添加辅热可有效减轻昂贵搅拌头的磨损。因此,采用底部辅热装置将Q960高强钢分别辅热至150℃和300℃后利用搅拌摩擦焊接技术完成钢板的焊接,并对焊缝微观组织和韧性进行分析。结果表明:底部添加辅热可有效消除板厚方向的温差,在150℃辅热时,Q960高强钢搅拌摩擦焊接头底部缺陷消失,但300℃辅热时,搅拌头下压力明显降低,接头底部又生成缺陷。辅热搅拌摩擦焊接时,接头峰值温度逐渐升高,冷却速度随辅热温度的提高而降低。150℃低温辅热时,析出物长大不明显,硬度略有降低,接头韧性明显改善;300℃高温辅热时,接头发生显著回火现象,析出物严重粗化,从而导致接头韧性急剧恶化。因此,低温辅热既可获得无缺陷接头,又可有效提高Q960高强钢接头韧性。
The wear of expensive stirring tools can be effectively reduced by adding auxiliary heat in friction stir welding of steel materials.For this purpose,the Q960 high-strength steel is heated to 150℃and 300℃by a bottom preheating device,and the microstructural evolution and impact toughness of the welded joints are analyzed.The results indicate that the temperature difference in the direction of the plate thickness can be effectively eliminated by adding auxiliary heat at the bottom.At 150℃auxiliary heating,the bottom defect of the friction stir welding joint of Q960 high-strength steel disappears;however,at 300℃auxiliary heating,the downforce of the stirring tool is significantly reduced,and defects are formed at the bottom of the joint.In the process of friction stir welding with auxiliary heat,the peak temperature of the joint increases gradually,and the cooling rate decreases with the increase of the auxiliary heat temperature.At 150℃low-temperature auxiliary heating,the growth of the precipitates is not obvious,the hardness is slightly reduced,and the impact toughness of the joint is obviously improved.At 300℃high-temperature auxiliary heating,the joint will be tempered significantly,and the precipitates will be severely coarsened,which will lead to sharp deterioration of the impact toughness of the joint.Hence,low-temperature auxiliary heating can not only obtain defect-free joints,but also effectively improve the toughness of Q960 high-strength steel joints.
作者
陶庭芳
王铮
虎雅雯
崔洪波
TAO Tingfang;WANG Zheng;HU Yawen;CUI Hongbo(School of Materials Science and Engineering,Guilin University of Technology,Guilin 541004,Guangxi,China)
出处
《材料工程》
北大核心
2025年第8期110-117,共8页
Journal of Materials Engineering
基金
广西自然科学基金(2021GXNSFBA196061)
广西科技基地和人才专项(2018AD19173)。
关键词
辅热搅拌摩擦焊接
Q960高强钢
微观组织
析出物
韧性
auxiliary heating friction stir welding
Q960 high-strength steel
microstructure
precipitate
toughness
