Microstructure and mechanical properties analysis of resistance spot welded joints of 22MnB5/DP980 dissimilar steel
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摘要: 利用MD-40中频逆变点凸焊设备，对1.2 mm厚22MnB5与1.6 mm厚DP980异种钢开展电阻点焊试验，结合拉伸试验、显微硬度测试、金相组织观察等方法，研究不同焊接电流与时间对22MnB5/DP980点焊接头成形质量、微观组织及力学性能的影响。结果表明：随焊接电流的增大，接头拉剪力呈现持续上升趋势，当焊接电流为11 kA时，拉剪力达到峰值16.81 kN；焊接时间的延长同样会使接头拉剪力不断提高，在焊接时间为400 ms时，拉剪力达到峰值17.23 kN，与焊接电流相比，焊接时间对接头拉剪力的提升作用更显著，但当焊接时间为400 ms时，会出现电极与材料粘连及飞溅现象，从而加剧电极的磨损。综合考虑焊接电流及时间对22MnB5/DP980焊接接头拉伸力学性能的影响，确定相对优异的焊接工艺参数为：电极压力0.2 MPa、焊接电流11 kA、焊接时间350 ms。焊接接头DP980钢侧热影响区存在软化现象，熔核区硬度高于热影响区，且焊接电流越大，该侧热影响区软化程度越严重；而22MnB5钢侧热影响区则发生硬化现象，热影响区硬度高于熔核区，接头的显微硬度值由高到低依次为22MnB5钢侧热影响区、熔核区、DP980钢侧热影响区。22MnB5/DP980焊接接头断裂方式为部分熔核拔出断裂，即熔核未完全拔出，拔出时沿熔核周围撕裂22MnB5侧母材，DP980侧无撕裂，熔核附着于DP980钢一侧。Abstract: Resistance spot welding experiments were conducted on 1.2 mm thick 22MnB5 and 1.6 mm thick DP980 dissimilar steels using MD-40 medium-frequency inverter spot welding equipment. By integrating techniques including tensile testing, microhardness measurements, and metallographic observations, the influences of varying welding currents and times on the formation quality, microstructure, and mechanical properties of 22MnB5/DP980 spot welded joints were investigated. The results indicated that with the increase of welding current, the tensile shear force of the joint continued to rise, reaching a peak of 16.81 kN at a welding current of 11 kA. Similarly, extending the welding time also continuously increased the tensile shear force, which peaked at 17.23 kN when the welding time was 400 ms. Compared with the welding current, welding time has a more significant effect on improving the tensile shear force of the joint. However, when the welding time reached 400 ms, electrode adhesion to the material and spattering occurred, thereby exacerbating electrode wear. Considering comprehensively the effects of welding current and time on the tensile properties of 22MnB5/DP980 welded joints, the relatively optimal welding parameters were determined as follows: electrode pressure of 0.2 MPa, welding current of 11 kA, and welding time of 350 ms. Softening occurred in the heat-affected zone (HAZ) on the DP980 steel side of the welded joint, and the hardness of the nugget zone was higher than that of the HAZ. Moreover, the larger the welding current, the more severe the softening of the HAZ on this side. In contrast, hardening took place in the HAZ on the 22MnB5 steel side, where the hardness was higher than that of the nugget zone. The microhardness values of the welded joint in descending order were as follows: HAZ on the 22MnB5 steel side, nugget zone, and HAZ on the DP980 steel side. The fracture mode of the 22MnB5/DP980 welded joint was partial nugget pull-out fracture, where the nugget was not completely pulled out. During the pull-out process, the 22MnB5 side base metal tore around the nugget, while no tearing observed on the DP980 side, and the nugget remained attached to the DP980 steel side.
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Key words:
- resistance spot welding /
- dissimilar steel /
- microstructure /
- mechanical properties
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图 3 不同焊接参数熔核区显微组织
Figure 3. Microstructure of the FZ under different welding parameters
(a)11 kA，350 ms；(b)8 kA，350 ms；(c)11 kA，250 ms
图 4 不同焊接参数22MnB5侧热影响区显微组织
(a)11 kA，350 ms；(b)8 kA，350 ms；(c)11 kA，250 ms
Figure 4. Microstructure of the HAZ on the 22MnB5 side under different welding parameters
图 5 不同焊接电流下接头显微硬度分布
Figure 5. Microhardness distribution of the joints with different welding currents
图 6 不同焊接时间下接头显微硬度分布
Figure 6. Microhardness distribution of the joints with different welding times
图 7 不同焊接电流下接头拉伸性能
(a)拉伸曲线；(b)拉剪力
Figure 7. Tensile properties of the joint with different welding currents
图 8 不同焊接时间下接头拉伸性能
(a)拉伸曲线；(b)拉剪力
Figure 8. Tensile properties of the joints with different welding times
表 1 22MnB5和DP980钢的化学成分
Table 1. Chemical compositions of 22MnB5 and DP980 steels
% Material C Si Mn P S B Cr Ti Mo Al Fe 22MnB5 0.21 0.28 1.35 0.003 0.17 0.036 0.005 Bal. DP980 0.08 0.393 2.2 0.008 0.0011 0.0019 0.05 0.18 0.032 Bal. 
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表 2 点焊工艺参数
Table 2. Welding process parameters
Test number welding current/kA Welding
time/msElectrode pressure/MPa 1 8 350 0.2 2 9 350 0.2 3 10 350 0.2 4 11 350 0.2 5 11 250 0.2 6 11 300 0.2 7 11 350 0.2 8 11 400 0.2
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[1] WANG C Y, YANG J, CHANG Y, et al. Development trend and challenge of advanced high strength automobile steels[J]. Iron and Steel, 2019, 54(2): 1-6. (王存宇, 杨洁, 常颖, 等. 先进高强度汽车钢的发展趋势与挑战[J]. 钢铁, 2019, 54(2): 1-6. doi: 10.13228/j.boyuan.issn0449-749x.20180284WANG C Y, YANG J, CHANG Y, et al. Development trend and challenge of advanced high strength automobile steels[J]. Iron and Steel, 2019, 54（2）: 1-6. doi: 10.13228/j.boyuan.issn0449-749x.20180284 [2] TANG Y S, SI Y, XU Z M, et al. Application and research progress of ultra-high strengh steel in automotive lightweight[J]. Heat Treatment of Metals, 2023, 48(10): 247-254. (唐远寿, 司宇, 徐正萌, 等. 超高强度钢在汽车轻量化中的应用及研究进展[J]. 金属热处理, 2023, 48(10): 247-254. doi: 10.13251/j.issn.0254-6051.2023.10.038TANG Y S, SI Y, XU Z M, et al. Application and research progress of ultra-high strengh steel in automotive lightweight[J]. Heat Treatment of Metals, 2023, 48（10）: 247-254. doi: 10.13251/j.issn.0254-6051.2023.10.038 [3] ZHANG P Y, ZHANG M, ZHOU L L, et al. Analysis of carbon migration phenomenon in dissimilar steel joints of 22MnB5 and QStE550TM[J]. Iron and Steel, 2024, 59(10): 86-95. (张朋彦, 张明, 周磊磊, 等. 22MnB5和QStE550TM的异种钢接头碳迁移现象分析[J]. 钢铁, 2024, 59(10): 86-95. doi: 10.13228/j.boyuan.issn0449-749x.20230723ZHANG P Y, ZHANG M, ZHOU L L, et al. Analysis of carbon migration phenomenon in dissimilar steel joints of 22MnB5 and QStE550TM[J]. Iron and Steel, 2024, 59（10）: 86-95. doi: 10.13228/j.boyuan.issn0449-749x.20230723 [4] JI Y Y, WANG W F, CHENG C J, et al. Study on microstructure and properties of hot formed steel/galvanized DP800 steel spot welded joints[J]. Hot Working Technology, 2022, 51(15): 50-53. (计遥遥, 王伟峰, 成昌晶, 等. 热成形钢/镀锌DP800钢点焊接头组织与性能研究[J]. 热加工工艺, 2022, 51(15): 50-53. doi: 10.14158/j.cnki.1001-3814.20202203JI Y Y, WANG W F, CHENG C J, et al. Study on microstructure and properties of hot formed steel/galvanized DP800 steel spot welded joints[J]. Hot Working Technology, 2022, 51（15）: 50-53. doi: 10.14158/j.cnki.1001-3814.20202203 [5] WANG E M, MI Z L, WEI Z C, et al. Resistance spot welding process and liquid metal embrittlement crack distribution of Q&P980 galvanized high-strength steel[J]. Journal of Material Engineering, 2023, 51(1): 85-94. (王恩茂, 米振莉, 卫志超, 等. Q&P980镀锌高强钢电阻点焊工艺及液态金属脆化裂纹分布[J]. 材料工程, 2023, 51(1): 85-94.WANG E M, MI Z L, WEI Z C, et al. Resistance spot welding process and liquid metal embrittlement crack distribution of Q&P980 galvanized high-strength steel[J]. Journal of Material Engineering, 2023, 51（1）: 85-94. [6] KONG L, LIU S Y, WANG M. Analysis and prediction of fracture modes of resistance spot welds in advanced high-strength steels[J]. Transactions of the China Welding Institution, 2020, 41(1): 12-17, 97-98. (孔谅, 刘思源, 王敏. 先进高强钢电阻点焊接头的断裂模式分析与预测[J]. 焊接学报, 2020, 41(1): 12-17, 97-98. doi: 10.12073/j.hjxb.20190104002KONG L, LIU S Y, WANG M. Analysis and prediction of fracture modes of resistance spot welds in advanced high-strength steels[J]. Transactions of the China Welding Institution, 2020, 41（1）: 12-17, 97-98. doi: 10.12073/j.hjxb.20190104002 [7] ZHANG M, ZHOU L L, LIANG E R, et al. Microstructure and properties analysis of welded joint of 22MnB5/QStE550TM dissimilar steel[J]. The Chinese Journal of Process Engineering, 2024, 24(7): 863-874. (张明, 周磊磊, 梁恩荣, 等. 22MnB5/QStE550TM异种钢焊接接头组织与性能分析[J]. 过程工程学报, 2024, 24(7): 863-874.ZHANG M, ZHOU L L, LIANG E R, et al. Microstructure and properties analysis of welded joint of 22MnB5/QStE550TM dissimilar steel[J]. The Chinese Journal of Process Engineering, 2024, 24（7）: 863-874. [8] WU C Y, LIU H J, WANG Q, et al. Research on the effect of Al content on microstructure and mechanical properties of laser welded joint of 22MnB5 steel[J]. Applied Laser, 2024, 44(11): 34-46. (吴晨雨, 刘海江, 汪乾, 等. Al元素含量对22MnB5钢激光焊接接头组织与力学性能影响研究[J]. 应用激光, 2024, 44(11): 34-46. doi: 10.14128/j.cnki.al.20244411.034WU C Y, LIU H J, WANG Q, et al. Research on the effect of Al content on microstructure and mechanical properties of laser welded joint of 22MnB5 steel[J]. Applied Laser, 2024, 44（11）: 34-46. doi: 10.14128/j.cnki.al.20244411.034 [9] KARBASIAN H, TEKKAYA A E. A review on hot stamping[J]. Journal of Material Processing Technology, 2010, 210(15): 2103-2118. doi: 10.1016/j.jmatprotec.2010.07.019 [10] ÇAVUŞOĞLU O, ÇAVUŞOĞLU O, YıLMAZOĞLU A G, et al. Microstructural features and mechanical properties of 22MnB5 hot stamping steel in different heat treatment conditions[J]. Journal of Materials Research and Technology, 2020, 9(5): 10901-10908. doi: 10.1016/j.jmrt.2020.07.043 [11] ZHAI Z J, CAO Y, ZHAO L, et al. Effect of heat input on microstructure and mechanical properties of DP980 laser welded steel[J]. Journal of Iron and Steel Research, 2020, 32(1): 66-73. (翟战江, 曹洋, 赵琳, 等. 热输入对DP980激光焊组织和力学性能的影响[J]. 钢铁研究学报, 2020, 32(1): 66-73. doi: 10.13228/j.boyuan.issn1001-0963.20190119ZHAI Z J, CAO Y, ZHAO L, et al. Effect of heat input on microstructure and mechanical properties of DP980 laser welded steel[J]. Journal of Iron and Steel Research, 2020, 32（1）: 66-73. doi: 10.13228/j.boyuan.issn1001-0963.20190119 [12] ZHU X O, LIU Z Q, YIN G L, et al. Microstructure and properties of resistance spot welding joints of TRIP590/CP780 dissimilar steel[J]. Ordnance Material Science and Engineering, 2023, 46(4): 40-45. (朱晓欧, 刘占起, 尹桂丽, 等. TRIP590/CP780异种钢电阻点焊接头组织与性能研究[J]. 兵器材料科学与工程, 2023, 46(4): 40-45. doi: 10.14024/j.cnki.1004-244x.20230711.002ZHU X O, LIU Z Q, YIN G L, et al. Microstructure and properties of resistance spot welding joints of TRIP590/CP780 dissimilar steel[J]. Ordnance Material Science and Engineering, 2023, 46（4）: 40-45. doi: 10.14024/j.cnki.1004-244x.20230711.002 [13] YANG K K, EL-SARI B, OLFERT V, et al. Expulsion prevention in resistance spot welding of dissimilar joints with ultra-high strength steel: An analysis of the mechanism and effect of preheating current[J]. Journal of Manufacturing Processes, 2024(124): 489-502. [14] YU Y M, LI Z G, LOU G D, et al. Study on mechanical properties of resistance spot welded joints with single pulse unequal thickness of 22MnB5/DP590[J]. Iron Steel Vanadium Titanium, 2024, 45(4): 181-188. (于永梅, 李治国, 娄国栋, 等. 单脉冲不等厚22MnB5/DP590电阻点焊接头的力学性能研究[J]. 钢铁钒钛, 2024, 45(4): 181-188.YU Y M, LI Z G, LOU G D, et al. Study on mechanical properties of resistance spot welded joints with single pulse unequal thickness of 22MnB5/DP590[J]. Iron Steel Vanadium Titanium, 2024, 45（4）: 181-188. [15] YOU J H, FENG Y, WEN T, et al. Influence of Nb alloying on welding properties of 22MnB5 PHS spot-weld[J]. Materials Reports, 2022, 36(S2): 367-371. (游建豪, 冯毅, 温彤, 等. Nb合金化对22MnB5热成形高强钢点焊性能的影响[J]. 材料导报, 2022, 36(S2): 367-371.YOU J H, FENG Y, WEN T, et al. Influence of Nb alloying on welding properties of 22MnB5 PHS spot-weld[J]. Materials Reports, 2022, 36（S2）: 367-371. [16] HE D Q, LIU H Q, LAI R L. Analysis of the process performance of resistance spot welding for MS1400/DP980 steel[J]. Transactions of the China Welding Institution, 2018, 39(4): 104-108, 133-134. (贺地求, 刘杭琪, 赖瑞林. MS1400/DP980钢的电阻点焊的工艺性能分析[J]. 焊接学报, 2018, 39(4): 104-108, 133-134. doi: 10.12073/j.hjxb.2018390105HE D Q, LIU H Q, LAI R L. Analysis of the process performance of resistance spot welding for MS1400/DP980 steel[J]. Transactions of the China Welding Institution, 2018, 39（4）: 104-108, 133-134. doi: 10.12073/j.hjxb.2018390105 [17] KRISHNAN V, AYYASAMY E, PARAMASIVAM V. Influence of resistance spot welding process parameters on dissimilar austenitic and duplex stainless steel welded joints[J]. Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering, 2021, 235(1): 12-23. doi: 10.1177/0954408920933528 [18] LOU G D. Study on microstrucrure and properties of DP590/22MnB5 resistance spot welding joints[D]. Shenyang: Shenyang University of Chemical Technology, 2023. (娄国栋. DP590/22MnB5电阻点焊接头组织与性能研究[D]. 沈阳: 沈阳化工大学, 2023.LOU G D. Study on microstrucrure and properties of DP590/22MnB5 resistance spot welding joints[D]. Shenyang: Shenyang University of Chemical Technology, 2023. [19] YU Y M, LOU G D, JING Y. Microstructure of 22MnB5/DP590 joint with unequal thickness by single-pulse resistance spot welding[J]. Welding & Joining, 2023(11): 13-19. (于永梅, 娄国栋, 荆毅. 22MnB5/DP590不等厚单脉冲电阻点焊接头组织[J]. 焊接, 2023(11): 13-19. doi: 10.12073/j.hj.20220527001YU Y M, LOU G D, JING Y. Microstructure of 22MnB5/DP590 joint with unequal thickness by single-pulse resistance spot welding[J]. Welding & Joining, 2023（11）: 13-19. doi: 10.12073/j.hj.20220527001 [20] CHEN X F, LI Z X, YANG D P, et al. Achieving excellent properties of resistance spot welded 2GPa-grade press hardened steel and galvanized DP980 steel via double-pulse[J]. Journal of Materials Research and Technology, 2024(28): 4475-4487. -
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