外加交变磁场对超细晶粒钢点焊质量的影响
摘要
作为新一代高性能钢铁结构材料代表的超细晶粒钢,因其晶粒超细化从而实现了性能的强韧化。但在焊接热循环作用下,焊接接头会出现晶粒长大,软化及强度下降等问题,从而降低了产品质量、可靠性和使用寿命。针对这个问题,本文探讨了外加交变磁场改善超细晶粒钢点焊接头质量的新方法。文章以400MPa超细晶粒钢为研究对象,系统分析了外加交变磁场对超细晶粒钢点焊接头质量的影响。
本文首先对点焊接头宏观形貌和晶粒形态进行分析。在选定焊接参数下,正常点焊接头截面接近矩形,外加磁场后,接头截面为椭圆形,并且在外加磁场作用下,熔核直径增大,焊点高度和焊透率略有降低。正常点焊时,熔核的凝固组织为单一粗大的柱状晶,方向性很强。外加磁场后,熔核内柱状晶方向性减弱,熔核中心及边缘出现不等量的等轴晶。研究分析表明,同一励磁电流下,外加反向磁场比同向磁场作用效果更强;同一磁场方向下,施加150A励磁电流较其他大小电流作用效果好。其次对接头的显微组织和力学性能进行研究。超细晶粒钢点焊熔核的显微组织为珠光体、马氏体和极少量铁素体。外加磁场后,熔核内组织分布更为细小均匀,并且熔核内平均硬度有所提高。拉剪试验结果表明,外加磁场后,点焊接头的抗剪切能力提高,采用向内磁场,施加150A励磁电流,接头的最大拉剪载荷较无磁场时提高了1.9%。最后对点焊接头内部缺陷进行分析。当电极压力不足时,熔核内部易出现裂纹、缩孔和疏松缺陷。在外加磁场作用下,熔核内缺陷得到不同程度的改善,同样,采用向内磁场,施加150A励磁电流时,磁场对缺陷的改善效果较好。
实验结果证明,选择合适的点焊工艺和磁场参数,外加交变磁场可以改变晶粒的结晶方向,改善一次、二次结晶组织,提高焊缝的力学性能,是一种很有发展前景的点焊质量控制方法。
As representative of high-performance steel material of new generation, ultra-fine grained steel realize, for its super-fine grain, realize the performance strengthening and toughening. But in welding processes, the welded joints of ultra-fine grained steel will be grain growth, softening and strength decline, which will reduce the product quality, reliability and service life. For this issue, the method, which is the quality improving of spot welding of ultra-fine grained steel in the external alternating magnetic field, will be discussed by this article. Taking 400MPa ultra-fine grained steel for an example, this paper systematically analyzes the effect of external alternating magnetic field on the quality of spot welded joint.
This paper analyzes the macro-features and crystal habit of spot welded joint first. Under the selection of welding parameter, the section of normal spot welded joint is close to rectangular, but which is ellipse in external magnetic field. And it has a greater nugget diameter, a smaller joint height and penetration rate in alternating magnetic field. The nugget of ultra-fine grained steel is made up of single and coarse columnar crystals under general spot weld process, which has strong orientation. When it is applied external magnetic field, the orientation of columnar in nugget is weakened and there are variable amounts of equiaxed crystals in the center and fringe of the nugget. The research indicates that, as the same magnetic current, the effect of reverse magnetic field is superior to that of the same magnetic field; as the same magnetic direction, the effect of 150A magnetic current is better than others. Second, the microstructure and mechanical properties are researched. The microstructure of spot welded joint of ultra-fine grained steel of made up of pearlite, martensite and little of ferrite. When it is applied external magnetic field, the structure distribution is more fine and uniform and the average hardness in the nugget increases. The result of tensile shear experiment shows that, compared to the normal spot welding, the load against tensile shear improved the 1.90% when applied reverse magnetic field and 150A magnetic current. Finally, the inner defect of spot welded joint is researched. When the electrode force is below, there are cracks and shrinkage in the nugget. When it is applied magnetic field, the defects in the nugget are improved to same degree, similarly, the improvement effect is the best for150A reverse magnetic.
It is obvious that external alternating magnetic field can modify the direction of crystallization, improve primary and secondary solidification structure, and increase the mechanical properties of spot welded joints. So this method has unexceptionable prospect in spot welding quality control.
本文首先对点焊接头宏观形貌和晶粒形态进行分析。在选定焊接参数下,正常点焊接头截面接近矩形,外加磁场后,接头截面为椭圆形,并且在外加磁场作用下,熔核直径增大,焊点高度和焊透率略有降低。正常点焊时,熔核的凝固组织为单一粗大的柱状晶,方向性很强。外加磁场后,熔核内柱状晶方向性减弱,熔核中心及边缘出现不等量的等轴晶。研究分析表明,同一励磁电流下,外加反向磁场比同向磁场作用效果更强;同一磁场方向下,施加150A励磁电流较其他大小电流作用效果好。其次对接头的显微组织和力学性能进行研究。超细晶粒钢点焊熔核的显微组织为珠光体、马氏体和极少量铁素体。外加磁场后,熔核内组织分布更为细小均匀,并且熔核内平均硬度有所提高。拉剪试验结果表明,外加磁场后,点焊接头的抗剪切能力提高,采用向内磁场,施加150A励磁电流,接头的最大拉剪载荷较无磁场时提高了1.9%。最后对点焊接头内部缺陷进行分析。当电极压力不足时,熔核内部易出现裂纹、缩孔和疏松缺陷。在外加磁场作用下,熔核内缺陷得到不同程度的改善,同样,采用向内磁场,施加150A励磁电流时,磁场对缺陷的改善效果较好。
实验结果证明,选择合适的点焊工艺和磁场参数,外加交变磁场可以改变晶粒的结晶方向,改善一次、二次结晶组织,提高焊缝的力学性能,是一种很有发展前景的点焊质量控制方法。
As representative of high-performance steel material of new generation, ultra-fine grained steel realize, for its super-fine grain, realize the performance strengthening and toughening. But in welding processes, the welded joints of ultra-fine grained steel will be grain growth, softening and strength decline, which will reduce the product quality, reliability and service life. For this issue, the method, which is the quality improving of spot welding of ultra-fine grained steel in the external alternating magnetic field, will be discussed by this article. Taking 400MPa ultra-fine grained steel for an example, this paper systematically analyzes the effect of external alternating magnetic field on the quality of spot welded joint.
This paper analyzes the macro-features and crystal habit of spot welded joint first. Under the selection of welding parameter, the section of normal spot welded joint is close to rectangular, but which is ellipse in external magnetic field. And it has a greater nugget diameter, a smaller joint height and penetration rate in alternating magnetic field. The nugget of ultra-fine grained steel is made up of single and coarse columnar crystals under general spot weld process, which has strong orientation. When it is applied external magnetic field, the orientation of columnar in nugget is weakened and there are variable amounts of equiaxed crystals in the center and fringe of the nugget. The research indicates that, as the same magnetic current, the effect of reverse magnetic field is superior to that of the same magnetic field; as the same magnetic direction, the effect of 150A magnetic current is better than others. Second, the microstructure and mechanical properties are researched. The microstructure of spot welded joint of ultra-fine grained steel of made up of pearlite, martensite and little of ferrite. When it is applied external magnetic field, the structure distribution is more fine and uniform and the average hardness in the nugget increases. The result of tensile shear experiment shows that, compared to the normal spot welding, the load against tensile shear improved the 1.90% when applied reverse magnetic field and 150A magnetic current. Finally, the inner defect of spot welded joint is researched. When the electrode force is below, there are cracks and shrinkage in the nugget. When it is applied magnetic field, the defects in the nugget are improved to same degree, similarly, the improvement effect is the best for150A reverse magnetic.
It is obvious that external alternating magnetic field can modify the direction of crystallization, improve primary and secondary solidification structure, and increase the mechanical properties of spot welded joints. So this method has unexceptionable prospect in spot welding quality control.
引文
1张贵峰,苗慧霞.超细晶粒钢的焊接方法及接头组织特征.焊管. 2007,30(2): 39~41
2 E. Aghion, B. Bronfin, H. Friedrich, et al. The Environmental Impact of New Magnesium Alloys on the Transportation Industry. Magnesium Technology. Charlotte. U.S.A. 2004,(3):14~18
3张富强,朱心昆,梅东生.微米级超细晶粒钢细化工艺的研究进展.金加论坛. 2007,(8):39~41
4屈朝霞,田志凌,何长红.超细晶粒钢及其焊接性.钢铁. 2000,35(2):71～72
5 M. Nikura, M. Fujioka, Y. Adachi, et al. New Concepts for Ultra-fine Grained Steel in Super Metal Project. Journal of Materials Processing Technology. 2007,29(6):5~9
6 Z. Lin, X. D. Zhang, J. G. Shan. Study on Laser Welded Heat-affected Zone in New Ultralow Carbon Bainitic Steel. Journal of University of Science and Technology Beijing. 2007,14(2):163~137
7田志淩 ,何长红,张晓牧. 400MPa级超细晶粒钢的焊接.焊接学报. 2001,22(6):2~3
8 J. W. Zhang, W. X. Whang, L. Zhang. Improving the Fatigue Property of Welded Joints for AZ31 Magnesium Alloy Ultrasonic Peening Treatment. China Welding. 2008,17(2):32~42
9张旭东,陈武柱,王成.超细晶粒钢激光焊接接头的组织性能研究.应用激光. 2000,20(3):105~106
10雷毅,余圣甫,许晓峰.我国微米级超细晶粒钢焊接技术研究现状.兵器材料科学与工程. 2005,28(3):45~47
11 S. Asai. Birth and Recent Actives of Electromagnetic Processing of Materials. ISIJ International. 1989,29(12):981~992
12 C. Vives. Effects of Electromagnetic Vibration on the Microstructure of Continuously Cast Aluminium Alloys. Materials Science and Engineering. 1993,173(3):170~172
13 D. R. Uhlmann, T. P. Seward, B. Chalmers. The Effect of Magnetic Fields on the Structure of Metal Alloy Castings. Transition Metal Chemistry. 1996,236(4): 527~530
14 T. A. El-Bassyouni. Effect of Electromagnetic Force on Aluminum Cast Structure. 1983,33(12):733~734
15毛大恒,严宏志.电磁搅拌对铝及其合金凝固和铸态组织的影响.轻合金加工技术. 1991,19(4):10~16
16邢书明.电场和磁场作用下的金属凝固.特种铸造及有色合金. 1998,(6):37~38
17罗君.纵向磁场作用下镁合金的交流钨极氩弧焊.沈阳工业大学硕士论文. 2007:9~10
18 D. C. Brown. The Effect of Electromagnetic Stirring and Mechanical Vibration on Arc Welding. Welding Journal. 1962,41(2):241~250
19 C. F. Tseng, W. F. Savage. The Effect of Arc Oscillation in Either the Transverse or Longitudinal Direction Has a Beneficial Effect on the Fusion Zone Microstructure and Tends to Reduce Sensitibity to Hot Cracking. Welding Journal. 1971,50(12):777~785
20李亭,史清宇,李红克,等.铝合金搅拌摩擦焊接头残余应力分布.焊接学报. 2007,28(6):105~108
21杨思乾,马铁军.多脉冲点焊与磁控制点缝焊技术及其现状.航空制造技术. 2005,35(9):38~39
22 Y. Watanabe, T. Takeda, H. Sato. Effect of Magnetic Field on Weld Zone by Spot-welding in Stainless Steel. ISIJ International. 2006,46(9):1292~1293
23张忠典,李冬青,尹孝辉.外加磁场对焊接过程的影响.焊接. 2002,12(3):10～14
24徐磊.外加可控磁场对电阻点焊熔核组织的影响.哈尔滨工业大学硕士论文. 2008
25尹月.外加直流磁场对超细晶粒钢点焊质量的影响.哈尔滨工业大学硕士论文. 2009:42~43
26 S. Asai. Recent Development and Prospect of Electromagnetic Processing of Materials. Science and Technology of Advanced Materials. 2000,1(4):191~200
27李克.利用高频磁场分离熔体中的非金属夹杂.金属学报. 2001,37(4):405～410
28王清. 60Si2Mn弹簧钢点焊研究.哈尔滨工业大学硕士论文. 1987:66~108
29 M. A.阿勃拉洛夫, P. Y.阿勃杜拉赫曼诺.电磁作用焊接技术.韦福水,路登平译.北京.机械工业出版社, 1988:1~60
30李海刚,殷咸青,罗键,等.用电磁搅拌提高LD10CS铝合金焊接接头的质量.焊接学报, 1998,19(12):100~104
31 M. G. Li, T. Tamura, O. Naoki. Effects of Magnetic Field and Eledtric Current on Solidification of AZ91D Magnesium Alloys Using an ElectromagneticVibration Technique. Journal of Alloys and Compounds. 2009,487(2):436~437
32林健,蔡志鹏,赵海燕.外加磁场作用方向对焊接残余应力的影响.机械工程学报. 2006,42(11):202~203
33 X. Li, Y. Fautrelle, Z. M. Ren, Morphological Instability of Cell and Dendrite During During Directional Solidification under a High Magnetic Field. 2008,56(13):3150~3158
34贾昌申,肖克民.用电磁搅拌提高20g钢埋弧自动焊焊缝质量.电焊机, 1987,17(4):14～17
35国旭明,钱百年,薛小怀,等.电磁搅拌对管线钢埋弧焊熔覆金属低温韧性的影响.金属学报, 2000,26(2):177~180
36张学锋,张芳.超级钢的开发应用现状及未来展望.冶金丛刊. 2007,167(1): 2~3
37浜崎正信.搭接电阻焊.尹克里译.国防工业出版社. 1997:23~25
38中国机械工程学会焊接学会电阻焊(Ⅲ)专业委员会编著.电阻焊理论与实践.机械工业出版社. 1994:319~398
39林永兵,林忠钦,来新民,等.电阻点焊熔核形成过程磁流体力学分析.焊接学报. 2006,27(7):41~42
40赵熹华.薄件点焊熔核旋流现象的形成.焊接学报. 1995,16(1):36~39
41王建元,陈长乐.磁场作用下的金属凝固研究进展.材料导报. 2006,20(5): 79~80
42 Y. B. Li, Z. Q, Lin, S. Jack HU. Magnetohydrodynamic Behaviors in a Resistance Spot Weld Nugget under Different Welding Current. Technological Sciences. 2008,51(9):1508~1510
44 Y. B. Li, Z. Q. Zhang. Numerical Analysis of Magnetic Fluid Dynamics Behaviors During Resistance Spot Welding. Journal of Applied Physics. 2007,101(5):5~7
45 H. Conrad. Infection of an Electric or Magnetic Field on the Liquid-solid Transformation in Materials and on the Microstructure of the Solid. Material Science and Engineer. 2000,(10):205~287
46高玉周. D6AC (45crnilmolav)超高强钢点焊焊接性及工艺研究.哈尔滨工业大学硕士论文. 1991
2 E. Aghion, B. Bronfin, H. Friedrich, et al. The Environmental Impact of New Magnesium Alloys on the Transportation Industry. Magnesium Technology. Charlotte. U.S.A. 2004,(3):14~18
3张富强,朱心昆,梅东生.微米级超细晶粒钢细化工艺的研究进展.金加论坛. 2007,(8):39~41
4屈朝霞,田志凌,何长红.超细晶粒钢及其焊接性.钢铁. 2000,35(2):71～72
5 M. Nikura, M. Fujioka, Y. Adachi, et al. New Concepts for Ultra-fine Grained Steel in Super Metal Project. Journal of Materials Processing Technology. 2007,29(6):5~9
6 Z. Lin, X. D. Zhang, J. G. Shan. Study on Laser Welded Heat-affected Zone in New Ultralow Carbon Bainitic Steel. Journal of University of Science and Technology Beijing. 2007,14(2):163~137
7田志淩 ,何长红,张晓牧. 400MPa级超细晶粒钢的焊接.焊接学报. 2001,22(6):2~3
8 J. W. Zhang, W. X. Whang, L. Zhang. Improving the Fatigue Property of Welded Joints for AZ31 Magnesium Alloy Ultrasonic Peening Treatment. China Welding. 2008,17(2):32~42
9张旭东,陈武柱,王成.超细晶粒钢激光焊接接头的组织性能研究.应用激光. 2000,20(3):105~106
10雷毅,余圣甫,许晓峰.我国微米级超细晶粒钢焊接技术研究现状.兵器材料科学与工程. 2005,28(3):45~47
11 S. Asai. Birth and Recent Actives of Electromagnetic Processing of Materials. ISIJ International. 1989,29(12):981~992
12 C. Vives. Effects of Electromagnetic Vibration on the Microstructure of Continuously Cast Aluminium Alloys. Materials Science and Engineering. 1993,173(3):170~172
13 D. R. Uhlmann, T. P. Seward, B. Chalmers. The Effect of Magnetic Fields on the Structure of Metal Alloy Castings. Transition Metal Chemistry. 1996,236(4): 527~530
14 T. A. El-Bassyouni. Effect of Electromagnetic Force on Aluminum Cast Structure. 1983,33(12):733~734
15毛大恒,严宏志.电磁搅拌对铝及其合金凝固和铸态组织的影响.轻合金加工技术. 1991,19(4):10~16
16邢书明.电场和磁场作用下的金属凝固.特种铸造及有色合金. 1998,(6):37~38
17罗君.纵向磁场作用下镁合金的交流钨极氩弧焊.沈阳工业大学硕士论文. 2007:9~10
18 D. C. Brown. The Effect of Electromagnetic Stirring and Mechanical Vibration on Arc Welding. Welding Journal. 1962,41(2):241~250
19 C. F. Tseng, W. F. Savage. The Effect of Arc Oscillation in Either the Transverse or Longitudinal Direction Has a Beneficial Effect on the Fusion Zone Microstructure and Tends to Reduce Sensitibity to Hot Cracking. Welding Journal. 1971,50(12):777~785
20李亭,史清宇,李红克,等.铝合金搅拌摩擦焊接头残余应力分布.焊接学报. 2007,28(6):105~108
21杨思乾,马铁军.多脉冲点焊与磁控制点缝焊技术及其现状.航空制造技术. 2005,35(9):38~39
22 Y. Watanabe, T. Takeda, H. Sato. Effect of Magnetic Field on Weld Zone by Spot-welding in Stainless Steel. ISIJ International. 2006,46(9):1292~1293
23张忠典,李冬青,尹孝辉.外加磁场对焊接过程的影响.焊接. 2002,12(3):10～14
24徐磊.外加可控磁场对电阻点焊熔核组织的影响.哈尔滨工业大学硕士论文. 2008
25尹月.外加直流磁场对超细晶粒钢点焊质量的影响.哈尔滨工业大学硕士论文. 2009:42~43
26 S. Asai. Recent Development and Prospect of Electromagnetic Processing of Materials. Science and Technology of Advanced Materials. 2000,1(4):191~200
27李克.利用高频磁场分离熔体中的非金属夹杂.金属学报. 2001,37(4):405～410
28王清. 60Si2Mn弹簧钢点焊研究.哈尔滨工业大学硕士论文. 1987:66~108
29 M. A.阿勃拉洛夫, P. Y.阿勃杜拉赫曼诺.电磁作用焊接技术.韦福水,路登平译.北京.机械工业出版社, 1988:1~60
30李海刚,殷咸青,罗键,等.用电磁搅拌提高LD10CS铝合金焊接接头的质量.焊接学报, 1998,19(12):100~104
31 M. G. Li, T. Tamura, O. Naoki. Effects of Magnetic Field and Eledtric Current on Solidification of AZ91D Magnesium Alloys Using an ElectromagneticVibration Technique. Journal of Alloys and Compounds. 2009,487(2):436~437
32林健,蔡志鹏,赵海燕.外加磁场作用方向对焊接残余应力的影响.机械工程学报. 2006,42(11):202~203
33 X. Li, Y. Fautrelle, Z. M. Ren, Morphological Instability of Cell and Dendrite During During Directional Solidification under a High Magnetic Field. 2008,56(13):3150~3158
34贾昌申,肖克民.用电磁搅拌提高20g钢埋弧自动焊焊缝质量.电焊机, 1987,17(4):14～17
35国旭明,钱百年,薛小怀,等.电磁搅拌对管线钢埋弧焊熔覆金属低温韧性的影响.金属学报, 2000,26(2):177~180
36张学锋,张芳.超级钢的开发应用现状及未来展望.冶金丛刊. 2007,167(1): 2~3
37浜崎正信.搭接电阻焊.尹克里译.国防工业出版社. 1997:23~25
38中国机械工程学会焊接学会电阻焊(Ⅲ)专业委员会编著.电阻焊理论与实践.机械工业出版社. 1994:319~398
39林永兵,林忠钦,来新民,等.电阻点焊熔核形成过程磁流体力学分析.焊接学报. 2006,27(7):41~42
40赵熹华.薄件点焊熔核旋流现象的形成.焊接学报. 1995,16(1):36~39
41王建元,陈长乐.磁场作用下的金属凝固研究进展.材料导报. 2006,20(5): 79~80
42 Y. B. Li, Z. Q, Lin, S. Jack HU. Magnetohydrodynamic Behaviors in a Resistance Spot Weld Nugget under Different Welding Current. Technological Sciences. 2008,51(9):1508~1510
44 Y. B. Li, Z. Q. Zhang. Numerical Analysis of Magnetic Fluid Dynamics Behaviors During Resistance Spot Welding. Journal of Applied Physics. 2007,101(5):5~7
45 H. Conrad. Infection of an Electric or Magnetic Field on the Liquid-solid Transformation in Materials and on the Microstructure of the Solid. Material Science and Engineer. 2000,(10):205~287
46高玉周. D6AC (45crnilmolav)超高强钢点焊焊接性及工艺研究.哈尔滨工业大学硕士论文. 1991