Process Parameter Optimization for Laser-Arc Hybrid Welding of Low-Carbon Bainite Steel Based on Response Surface Methodology

Jie Yu; Chuang Cai; Jia Xie; Ying Liang; Jiasen Huang; Zhijie Liu; Yonghong Liu

doi:10.3788/CJL202249.1602018

Journals >Chinese Journal of Lasers >Volume 49 >Issue 16 >Page 1602018 > Article

Chinese Journal of Lasers
Vol. 49, Issue 16, 1602018 (2022)

Process Parameter Optimization for Laser-Arc Hybrid Welding of Low-Carbon Bainite Steel Based on Response Surface Methodology

Jie Yu, Chuang Cai^*, Jia Xie, Ying Liang, Jiasen Huang, Zhijie Liu, and Yonghong Liu

Author Affiliations

Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, Sichuan, China

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DOI: 10.3788/CJL202249.1602018 Cite this Article Set citation alerts

Jie Yu, Chuang Cai, Jia Xie, Ying Liang, Jiasen Huang, Zhijie Liu, Yonghong Liu. Process Parameter Optimization for Laser-Arc Hybrid Welding of Low-Carbon Bainite Steel Based on Response Surface Methodology[J]. Chinese Journal of Lasers, 2022, 49(16): 1602018 Copy Citation Text

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Fig. 1. Schematics of laser-arc hybrid welding system and groove

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Fig. 2. Schematic of weld measurement area

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Fig. 3. Influence curves of weld forming coefficient. (a) Scattered point distribution; (b) single factor disturbance curves; (c) contour lines characterizing interactions of P and V_w with ψ；(d) response surface characterizing interactions of P and V_w with ψ；(e) contour lines characterizing interactions of P and V_f with ψ；(f) response surface characterizing interactions of P and V_f with ψ；(g) contour lines characterizing interactions of V_w and V_f with ψ；(h) response surface characterizing interactions of V_w and V_f with ψ

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Fig. 4. Influence curves of laser area ratio. (a) Scattered point distribution; (b) single factor disturbance curves; (c) contour lines characterizing interactions of P and V_w with R; (d) response surface characterizing interactions of P and V_w with R; (e) contour lines characterizing interactions of P and V_f with R; (f) response surface characterizing interactions of P and V_f with R; (g) contour lines characterizing interactions of V_w and V_f with R; (h) response surface characterizing interactions of V_w and V_f with R

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Fig. 5. Typical weld morphologies under optimized process parameters (P＝4250 W, V_w＝16 mm/s, and V_f＝13 m/min). (a) Front side; (b) back side; (c) cross-section

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Element	C	Si	Mn	Cr	Ni	Mo	Cu	Nb	Ti	Co	Fe
Low-carbon bainite steel	0.04	0.3	1.35	0.33	0.53	0.34	0.35	0.03	0.02	<0.01	Bal.
Welding wire	0.06	0.37	1.49	0.34	2.84	0.35	0.1	－	－	－	Bal.

Table 1. Chemical compositions of low-carbon bainite steel and welding wire (mass fraction, %)

Experimental factor	Value
Experimental factor	Low level	Zero level	High level
P/W	4000	4250	4500
V_w/(mm·s^－1)	14	16	18
V_f/(m·min^－1)	12	13	14

Table 2. Process parameter levels for laser-MAG hybrid welding of low-carbon bainite steel

Process No.	Laser power P/W	Welding speed V_w /(mm·s^－1)	Wire feeding speed V_f /(m·min^－1)	Weld forming coefficient ψ	Laser area ratio R
1	4000	16.00	14.00	1.124	0.2355
2	4250	16.00	13.00	1.278	0.2589
3	4250	14.00	12.00	1.470	0.2119
4	4000	14.00	13.00	1.406	0.3054
5	4000	16.00	12.00	1.009	0.1634
6	4250	16.00	13.00	1.116	0.2280
7	4500	16.00	14.00	1.283	0.2806
8	4250	18.00	12.00	0.874	0.2196
9	4250	14.00	14.00	1.574	0.6008
10	4000	18.00	13.00	0.884	0.1103
11	4250	16.00	13.00	1.089	0.2093
12	4500	16.00	12.00	1.014	0.1830
13	4250	16.00	13.00	1.064	0.1899
14	4500	18.00	13.00	0.919	0.1310
15	4250	16.00	13.00	1.100	0.2199
16	4500	14.00	13.00	1.216	0.2562
17	4250	18.00	14.00	1.068	0.1928

Table 3. Statistics of test parameters and response values for laser-MAG hybrid welding of low-carbon bainite steel

Process No.	Front appearance of weld surface	Cross-sectional morphology	Weld formation
2			Excess weld accumulation
5			Lack of penetration
6			Good form
9			Excessive penetration and overlap
13			Undercut
15			Pores
16			Good form
17			Undercut

Table 4. Weld formation and cross-sectional morphology of low-carbon bainitic steel joint by laser-MAG hybrid welding

Source	Sum of squares	Degree of freedom	Mean square	F value	P value	Reliability
Model	0.59	9	0.066	8.80	0.0045	Significant
A	1.075×10^－5	1	1.075×10^－5	1.434×10^－3	0.9709
B	0.46	1	0.46	61.44	0.0001
C	0.058	1	0.058	7.76	0.0271
AB	0.013	1	0.013	1.70	0.0958
AC	5.863×10^－3	1	5.863×10^－3	0.78	0.4060
BC	2.015×10^－3	1	2.015×10^－3	0.27	0.6203
A²	0.028	1	0.028	3.70	0.2335
B²	0.014	1	0.014	1.89	0.2118
C²	0.015	1	0.015	1.96	0.2041
Residual	0.053	7	7.502×10^－3
Lack of fitting value	0.023	3	7.818×10^－3	1.08	0.4538	Not significant
Pure error	0.029	4	7.266×10^－3
Total	0.65	16	0.066

Table 5. Variance analysis of models for weld forming coefficient model

Source	Sum of squares	Degree of freedom	Mean square	F value	P value	Reliability
Model	0.19	9	0.021	6.61	0.0105	Significant
A	1.638×10^－4	1	1.638×10^－4	0.052	0.8254
B	0.11	1	0.11	36.15	0.0005
C	0.039	1	0.039	12.63	0.0093
AB	1.222×10^－3	1	1.222×10^－3	0.39	0.5516
AC	1.626×10^－4	1	1.626×10^－4	0.052	0.8261
BC	8.621×10^－3	1	8.621×10^－3	2.76	0.0989
A²	0.011	1	0.011	3.62	0.1407
B²	4.135×10^－3	1	4.135×10^－3	1.32	0.2878
C²	9.002×10^－3	1	9.002×10^－3	2.88	0.1334
Residual	0.022	7	3.125×10^－3
Lack of fitting value	0.019	3	6.427×10^－3	9.92	0.0252	Not significant
Pure error	2.591×10^－3	4	6.476×10^－4
Total	0.21	16