Mechanism of 304 stainless steel underwater flux-cored arc cutting
-
摘要: 药芯割丝电弧切割(flux-cored wire arc cutting,FCAC)作为一种高效、低成本、安全的水下切割方法，具有广阔的应用前景. 由于水下复杂环境的干扰，该方法的不锈钢切割机理仍不明确，采用工艺试验、水下观测和数值模拟相结合的方法对水下割口成形机理进行研究. 首先通过工艺试验确定水下切割相关特征参数；其次采用半椭球体热源模拟切割热源，并根据试验观测设置热源的运动和切换方式；最后对工件进行网格划分和水下边界条件设置，使用生死单元法动态模拟切割中熔融金属的去除；对工件上特定点的模拟和实际温度以及切割后的模拟割口与实际割口形貌进行了研究对比，验证该方法数值模拟的准确性. 结果表明，水下电弧切割不锈钢割口主要分为“/ \”型、“| |”型和“\ /”型3种形貌. 通过高速摄像观察得出，水下不锈钢切割过程由多个周期型连续穿孔过程组成，通过模拟进行验证，对割口成形过程进行有效预测，有助于进一步优化工艺并进行有效控制.Abstract: As a high-efficiency, low-cost, and safe underwater cutting method, flux-cored wire arc cutting (FCAC) has broad application prospects. Due to the interference of the underwater complex environment, the stainless steel arc cutting mechanism of this method is still unclear. This research uses a combination of process tests, high-speed camera observation, and numerical simulation. Firstly, the relevant characteristic parameters of underwater cutting are determined through the process test; secondly, the semi-ellipsoid heat source is used to simulate the cutting heat source, and the movement and switching mode of the heat source is set according to the experimental observation; finally, the workpiece is meshed and ascertained the underwater boundary condition, the "birth and death" element method is applied to simulate the removal of molten metal during cutting; by comparing the simulated and actual temperature of measurement point and the kerf after cutting. The results showd that the kerf of underwater flux-arc cutting stainless steel is mainly divided into three types of shapes: "/ \" type, "| |" type and "\ /" type. The underwater stainless steel cutting process consists of multiple periodic continuous perforation processes observed by high-speed camera. It is also validated by simulation to predict the kerf forming process effectively, which helps to further optimize the process and control it effectively.
-
-
![]()
图 1 水下切割系统示意图
Figure 1. Underwater cutting system structure. (a) pressure vessel; (b) pressure vessel interior cutting structure
![]()
图 2 不同工艺参数下典型割口宽度形貌
Figure 2. Morphology of kerf width under different process parameters. (a) cutting current; (b) cutting voltage; (c) water depth
![]()
图 3 割口边缘显微组织分布
Figure 3. Microstructure distribution at the edge of the kerf. (a) macroscopic morphology of the kerf; (b) metal remelting zone; (c) heat affected zone; (d) base metal
![]()
图 8 热电偶分布(mm)
Figure 8. Thermocouple distribution. (a) scaffold model; (b) spacing of temperature measuring hole on the upper surface; (c) depth of temperature measuring hole
![]()
图 9 试验与模拟割口形貌对比
Figure 9. Comparison of experment and simulated kerf morphology. (a) expermental kerf morphology; (b) simulated kerf morphology
![]()
图 10 试验与模拟割口热循环曲线对比
Figure 10. Comparison of thermal cycling curves of experment and simulated kerf. (a) 35 V experimental curve; (b) 40 V experimental curve; (c) 45 V experimental curve; (d) 35 V simulated curve; (e) 40 V simulated curve; (f) 45 V simulated curve
表 1 水下切割试验参数
Table 1 Underwater cutting test parameters
组别 水深
h/m切割电流
I/A切割电压
U/V切割速度
v/(mm·s−1)a 0.2 400,450,500 40 130 b 0.2 450 35,40,45 130 c 50,100,150 450 45 130 
下载: 导出CSV
表 2 304不锈钢的热物理性能参数
Table 2 Thermophysical properties parameters of 304 stainless steel
温度
T/℃比热容
c/(J·kg·℃−1)热导率
λ/(W·m−1·℃−1)弹性模量
E/GPa泊松比 $\nu $ 屈服强度
ReL/MPa线性膨胀系数
α/10−6 ℃−120 442 15.0 200 0.278 230 19 200 515 17.5 185 0.288 184 19 400 563 20.0 170 0.298 132 19 600 581 22.5 153 0.313 105 19 800 609 25.5 135 0.327 77 19 1 000 631 28.3 96 0.342 50 19 1 200 654 31.1 50 0.350 10 19 1 340 669 33.1 10 0.351 10 19 1 390 675 66.2 10 0.353 10 19 2 000 675 66.2 10 0.357 10 19
下载: 导出CSV
-
[1] 施佳慧, 王俭辛, 黎文航, 等. 药芯割丝水下湿式电弧切割割口成形及热影响区组织分析[J]. 焊接学报, 2017, 38(2): 97 − 100. Shi Jiahui, Wang Jianxin, Li Wenhang, et al. Underwater wet flux-cored arc cutting kerf formation and heat-affected zone microstructure analysis[J]. Transactions of the China Welding Institution, 2017, 38(2): 97 − 100.
[2] Xu C S, Guo N, Zhang X, et al. In situ X-ray imaging of melt pool dynamics in underwater arc welding[J]. Materials & Design, 2019, 179: 107899.
[3] Świerczyńska A, Fydrych D, Rogalski G. Diffusible hydrogen management in underwater wet self-shielded flux cored arc welding[J]. International Journal of Hydrogen Energy, 2017, 42(38): 24532 − 24540. doi: 10.1016/j.ijhydene.2017.07.225
[4] Yang Q, Han Y, Jia C, et al. Impeding effect of bubbles on metal transfer in underwater wet FCAW[J]. Journal of Manufacturing Processes, 2019, 45: 682 − 689. doi: 10.1016/j.jmapro.2019.08.013
[5] Guo N, Du Y, Feng J, et al. Study of underwater wet welding stability using an X-ray transmission method[J]. Journal of Materials Processing Technology, 2015, 225: 133 − 138. doi: 10.1016/j.jmatprotec.2015.06.003
[6] Jia C, Zhang Y, Wu J, et al. Comprehensive analysis of spatter loss in wet FCAW considering interactions of bubbles, droplets, and arc – Part 1: Measurement and improvement[J]. Journal of Manufacturing Processes, 2019, 40: 122 − 127. doi: 10.1016/j.jmapro.2019.03.013
[7] 李志刚, 杨丽婷, 黄卫等. 水深环境下湿法焊接声压替代图像信号可行性分析[J]. 焊接学报, 2020, 41(8): 34 − 38. Li Zhigang, Yang Liting, Huang Wei, et al. Feasibility analysis of replacing image signal with a sound pressure of wet welding in deepwater environment[J]. Transactions of the China Welding Institution, 2020, 41(8): 34 − 38.
[8] Li W, Zhao J, Wang Y, et al. Research on underwater flux-cored arc cutting mechanism based on simulation of kerf formation[J]. Journal of Manufacturing Processes, 2019, 40: 169 − 177. doi: 10.1016/j.jmapro.2019.03.010
[9] Chen H, Guo N, Shi X, et al. Effect of hydrostatic pressure on protective bubble characteristic and weld quality in underwater flux-cored wire wet welding[J]. Journal of Materials Processing Technology, 2018, 259: 159 − 168. doi: 10.1016/j.jmatprotec.2018.04.037
[10] Wang J, Shi J, Wang J, et al. Numerical study on the temperature field of underwater flux-cored wire arc cutting process[J]. International Journal of Advanced Manufacturing Technology, 2017, 91: 1 − 10. doi: 10.1007/s00170-016-9713-y
[11] Li W, Zhao J, Wang J, et al. Research on arc cutting mechanism and procedure of flux-cored cutting wire in water[J]. The International Journal of Advanced Manufacturing Technology, 2018, 98: 2895 − 2904. doi: 10.1007/s00170-018-2438-3
[12] Parshin S, Levchenko A, Wang P, et al. Mathematical analysis of the influence of the flux-cored wire chemical composition on the electrical parameters and quality in the underwater wet cutting[J]. Advances in Materials Science, 2021, 21(1): 77 − 89. doi: 10.2478/adms-2021-0006
[13] Zhao B, Chen J, Jia C, et al. Numerical analysis of molten pool behavior during underwater wet FCAW process[J]. Journal of Manufacturing Processes, 2018, 32: 538 − 552. doi: 10.1016/j.jmapro.2018.03.020
计量
- 文章访问数: 217
- HTML全文浏览量: 6
- PDF下载量: 17
