Zarei Akbar, Akbari Mohammad, Abdollahi Ali, Soleimanimehr Hamid
Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
Aerospace and Energy Conversion Research Center, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
Heliyon. 2024 Oct 29;10(21):e39954. doi: 10.1016/j.heliyon.2024.e39954. eCollection 2024 Nov 15.
Welding with fiber laser for two distinct stainless steel types was performed to join with the martensitic carbon steel (AISI 1060) in order to assess the effect of laser welding operating parameters for two dissimilar materials on the weld characterization thorough experimental design method and numerical investigation. A full central composite design (CCD) matrix in accordance with the response surface methodology (RSM) was developed to represent the responses variations by equations including quadratic and nonlinear interaction terms. Different laser welding parameters were taken into account, such as laser power, linear speed of welding, focal distance of the beam, and beam deviation. The responses considered were the temperature field next to the melt pool border line, the maximum penetration depth of the fusion zone and the ultimate tensile strength of the dissimilar weld joint. Additionally, the variation of the microstructure fusion zone and adjacent areas and failure mechanism of the weld joint were evaluated. The experimental results indicate that the temperature field measured at the vicinity of the melt pool fusion line with both 304 and 420 stainless steel which primarily influenced by the incident power of the laser and linear velocity of beam, respectively. Additionally, the numerical simulation results are in good agreement with temperature experimental results at vicinity of fusion line where the temperature measured, experimentally. Apart from this, at the center of the fusion zone, the temperature clearly predicts via numerical simulation results which is not possible to assess experimentally. A clear comparison between the temperature distribution with different joint configuration illustrates that distinct relation between the temperature variation rate and different thermal conductivity coefficient of AISI 1060 with different AISI 304 and 420 joint configuration resulted different temperature distribution. The weld joint microstructure for 420 stainless steel-AISI 1060 steel joint at fusion boundary zone consists of columnar dendrites and skeletal columnar ferrite. At the center of fusion zone, a cellular-type structure is seen. For 304 stainless steel joint, the fusion zone has composed of a remarkable part of skeletal delta-ferrite and dendritic microstructure at austenite matrix microstructure. The fracture section of 304 steel has a ductile fracture and the depth of fracture dimples and cavities toward 304 stainless steel are higher than AISI 1060 steel.
对两种不同类型的不锈钢进行光纤激光焊接，以与马氏体碳钢（AISI 1060）连接，从而通过实验设计方法和数值研究来评估两种不同材料的激光焊接操作参数对焊缝特性的影响。根据响应面方法（RSM）开发了一个完整的中心复合设计（CCD）矩阵，以通过包含二次项和非线性相互作用项的方程来表示响应变化。考虑了不同的激光焊接参数，如激光功率、焊接线速度、光束焦距和光束偏差。所考虑的响应包括熔池边界线附近的温度场、熔合区的最大熔深以及异种焊缝接头的极限抗拉强度。此外，还评估了微观结构熔合区和相邻区域的变化以及焊缝接头的失效机制。实验结果表明，在熔池熔合线附近测量的温度场，对于304和420不锈钢，分别主要受激光入射功率和光束线速度的影响。此外，数值模拟结果与熔合线附近温度的实验结果吻合良好，而该温度是通过实验测量的。除此之外，在熔合区中心，温度通过数值模拟结果可以清晰预测，而这是无法通过实验评估的。不同接头配置下温度分布的清晰比较表明，AISI 1060与不同的AISI 304和420接头配置具有不同的热导率系数，这导致了温度变化率与温度分布之间的明显关系。420不锈钢 - AISI 1060钢接头在熔合边界区的焊缝微观结构由柱状枝晶和骨架柱状铁素体组成。在熔合区中心，可以看到蜂窝状结构。对于304不锈钢接头，熔合区在奥氏体基体微观结构中由显著部分的骨架δ - 铁素体和枝晶微观结构组成。304钢的断裂截面为韧性断裂，向304不锈钢方向的断裂韧窝和空洞深度高于AISI 1060钢。
