大尺寸Mo-1板轧制工艺研究

Investigation on Rolling Process for Mo-1 Plate of Large Size

研究了加热温度、初火次变形率、退火温度等工艺参数对大尺寸Mo-1板组织和性能的影响。按照实验设计的4种热轧方案和工艺流程,采用350mm二辊不可逆式轧机和马弗炉对Mo-1板坯进行热轧、退火及温轧、冷轧实验;用金相显微镜观察了热轧及退火的组织;测试了0.2mm厚的成品钼板力学性能。结果表明,轧制温度选在1250℃,初火次加工率选为37.5%,加工的Mo-1板综合性能比较好;热轧后的中间退火直接决定着后续工序的成败,退火温度应控制在850℃左右,保温时间应小于60min;为了减少热轧板坯表面和内部温差,改善板材组织和性能的各向异性,热轧时应预热轧辊,预热温度为200￣300℃;采用换向轧制可提高板材的塑性、冲击韧性等,各向异性明显降低。

The effects of heating temperature,reduction for the first time,and annealing temperature on the structure and properties of large size Mo-1 plate were investigated.According to the four kinds of heat rolling program and process which was designed previously, the tests of working and heat treatment were performed on the inreversible rolling mill with two roll of 350 mm and the muffle furnace. The microstructure after heating roiling and annealing was observed by metallography microscope,and the mechanical properties of finished Mo plate with 0.2 mm in thickness was tested.The results show that the Mo-1 plate annealed at the temperature of 1 250℃ and worked in reduction of 37.5% for the first time is possessed of the better comprehensive properties.Owing to the intermediate annealing is the key process for the consequent operations, the annealing temperature shuld be controlled at about 850℃,and the duration less than 60 min. The rolls have to be preheated before rolling in order to decreasing the temperature difference between out and inner of the plates. The preheating temperature is about 200-300℃.By means of alternative roiling process,the plasticity and toughness of the plate can be improved and the anisotropy decreased obviously.