A new hot forming process of a hot-rolled 2205 duplex stainless/AH36 low-carbon steel bimetal composite (2205/AH36 BC) was proposed in this study, using the Gleeble 3500 thermal-mechanical simulator and hot bending tools. The deformation characteristics of 2205/AH36 BC were studied by hot tensile tests at temperatures from 950 to 1250 °C and strain rates ranging from 0.01 to 1 s^–1. The tensile temperature has a great influence on the peak flow stress of the bimetal composite. The main microstructure evolution mechanisms, including dynamic recovery (DRV) and dynamic recrystallization (DRX), changed with the deformation temperatures. The different strain rates and the change of strain rates during the deformation process have an influence on the flow behavior of the bimetal composite. During the hot bending process, qualified parts could be formed successfully without obvious cracks in the interfacial zone. Phase and grain orientation spread (GOS) maps of specimens after hot tensile and forming tests were obtained by the electron backscatter diffraction (EBSD) technique to study the microstructure evolution, respectively. It is found that the effect of the working temperature on microstructure evolution is larger than that of the stacking sequence for 2205/AH36 BC. The considerable geometrically necessary dislocation (GND) accumulation occurs around the interface of 2205/AH36 BC under all imposed working conditions after the hot bending process, due to the interfacial micro-defects and complex stress states.

中文翻译：

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2205 / AH36双金属复合材料热成形新工艺的变形特性及组织演变的研究

本研究提出了一种新的热轧工艺，该工艺采用Gleeble 3500热机械模拟器和热弯曲工具对2205双相不锈钢/ AH36低碳钢双金属复合材料（2205 / AH36 BC）进行热轧。通过在950至1250°C的温度和0.01至1 s ^–1的应变速率下的热拉伸试验研究了2205 / AH36 BC的变形特性。拉伸温度对双金属复合材料的峰值流应力有很大的影响。随着变形温度的变化，主要的微观组织演化机制，包括动态恢复（DRV）和动态再结晶（DRX）。变形过程中不同的应变率和应变率的变化对双金属复合材料的流动行为有影响。在热弯曲过程中，可以成功地形成合格的零件，而在界面区域没有明显的裂纹。通过电子反向散射衍射（EBSD）技术分别获得了热拉伸和成形试验后的试样的相和晶粒取向扩展（GOS）图，以研究组织的演变。发现工作温度对显微组织演变的影响大于2​​205 / AH36 BC的堆积顺序。由于界面微缺陷和复杂的应力状态，在热弯曲工艺之后的所有施加的工作条件下，在2205 / AH36 BC的界面周围都会发生相当大的几何上必要的位错（GND）堆积。