Effect of GMAW Process and Material Conditions on DP 780 and TRIP 780 Welds
Effect of GMAW Process and Material Conditions on DP 780 and TRIP 780 Welds
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GMAW 工艺和材料条件对 DP 780 和 TRIP 780 焊接的影响
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
C. Albright
中科院分区：
文献类型：
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作者：
N. Kapustka;C. Conrardy;S. Babu;C. Albright
为了减轻车辆重量和提高碰撞性能，汽车制造商推出了更高强度等级的先进高强度钢（AHSS）。为了有效地使用这些材料，必须了解材料和工艺条件对气体保护金属极电弧（GMA）焊接性能的影响。这项工作的目的是表征材料预应变，冷却速率条件（焊接热输入和夹具散热器），填充金属的选择，稀释，和后烘烤的GMA焊缝上的涂层双相（DP）和相变诱发塑性（TRIP）钢的微观结构和力学性能的影响。研究的主要材料是DP 780和TRIP 780;为了进行比较，对DP 980进行了有限的工作。DP钢表现出不同程度的热影响区（HAZ）硬化和软化取决于材料等级，预应变，和冷却速率条件。TRIP 780的相对高的铝含量允许保留的铁素体存在于HAZ的所有区域中，以及沿着焊接界面的连续的粗铁素体区域。这导致TRIP 780具有比DP 780更低的峰值HAZ硬度。熔合区的显微组织和硬度被发现受到基体金属化学、冷却速率条件和填充金属成分的影响。填充金属强度不影响TRIP 780搭接或对接接头焊缝或DP 780对接接头焊缝的静态或动态拉伸性能。TRIP 780和DP 780对接接头均在软热影响区失效。搭接接头试验的结果表明，强度的变化较大，这是由于焊缝根部的孔隙率。
The drive to reduce vehicle weight and improve crash performance has led automotive manufacturers to introduce higher-strength grades of advanced high-strength steels (AHSS). For these materials to be used effectively, the influence of material and process conditions on gas metal arc (GMA) weld properties must be understood. The objective of this work was to characterize the effects of material prestrain, cooling rate conditions (welding heat input and fixture heat sink), filler metal selection, dilution, and postbaking on the microstructure and mechanical properties of GMA welds on coated dual-phase (DP) and transformation-induced plasticity (TRIP) steels. The primary materials studied were DP 780 and TRIP 780; for comparison purposes a limited amount of work was conducted with DP 980. The DP steels showed varying degrees of heat-affected zone (HAZ) hardening and softening depending on the material grade, prestrain, and cooling rate condition. The relatively high aluminum content of the TRIP 780 allowed retained ferrite to be present in all regions of the HAZ, along with a continuous region of coarse ferrite along the weld interface. This resulted in the TRIP 780 having lower peak HAZ hardness than the DP 780. Fusion zone microstructure and hardness were found to be affected by the base metal chemistry, the cooling rate condition, and the filler metal composition. Filler metal strength did not affect the static or dynamic tensile properties of either the TRIP 780 lap or butt joint welds, or the DP 780 butt joint welds. All of the TRIP 780 and DP 780 butt joints failed in the soft HAZ. The results of the lap joint tests showed a greater variation in strength that is attributed to porosity at the root of the weld.