Mansur Vinicius Machado, Mansur Raquel Alvim de Figueiredo, Carvalho Sheila Medeiros de, Siqueira Rafael Humberto Mota de, Lima Milton Sergio Fernandes de
Photonics Divison, Institute for Advanced Studies, 12228-001, Sao Jose dos Campos, SP, Brazil.
Department of Mechanical Engineering, Federal University of Espirito Santo, 29075-910, Vitoria, ES, Brazil.
Heliyon. 2021 Dec 15;7(12):e08601. doi: 10.1016/j.heliyon.2021.e08601. eCollection 2021 Dec.
Dual Phase steels are one of the most used advanced high-strength materials in the industry, due to its combination of a ductile ferritic matrix and disperse hard martensite islands, which provide outstanding mechanical properties for components to be cold stamped. This work investigated fiber laser welding applicability in Dual Phase 600 1.6 mm thick steel sheets, evaluating potential welding impacts on properties of the material for industrial applications. A first set of bead-on-plate welds was generated to define best parameters for subsequent tests. A second set was prepared, consisting of butt joints welded in the optimized condition. Weld microstructure was characterized as 100% martensitic at fusion zone (FZ), with growing fractions of ferrite at Heat Affected Zone (HAZ) as one moves away from fusion line. Hardness is around 60% higher at FZ than at BM, being maximum at supercritical HAZ due to its highly refined microstructure and HAZ softening was not observed. Tensile and Erichsen cupping tests presented similar strength results between welded and non-welded specimens, with slight ductility reduction. Finally, numeric simulations based on Finite Element Analysis were carried out to estimate temperature evolution, phase proportions, residual stresses and distortion levels, achieving excellent agreement with experimental results.
双相钢是工业中最常用的先进高强度材料之一，因为它具有韧性铁素体基体和弥散硬化马氏体岛的组合，这为冷冲压部件提供了出色的机械性能。这项工作研究了光纤激光焊接在1.6毫米厚的双相600钢板中的适用性，评估了对工业应用材料性能的潜在焊接影响。生成了第一组平板堆焊焊缝，以确定后续测试的最佳参数。制备了第二组，由在优化条件下焊接的对接接头组成。焊缝微观结构在熔合区（FZ）为100%马氏体，随着远离熔合线，热影响区（HAZ）中铁素体比例增加。FZ处的硬度比母材高约60%，在超临界热影响区达到最大值，这是由于其高度细化的微观结构，且未观察到热影响区软化。拉伸试验和埃里克森杯突试验表明，焊接和未焊接试样之间的强度结果相似，但延展性略有降低。最后，基于有限元分析进行了数值模拟，以估计温度演变、相比例、残余应力和变形水平，与实验结果取得了很好的一致性。
