大口径厚壁管道热挤压成形过程微观组织模拟及实验研究
|
摘要
针对某型核能发电用P91大口径厚壁无缝管道进行了不同挤压比条件下的垂直正挤压成形过程缩比数值模拟,研究了管道微观组织在挤压过程中的演变规律。研究表明:挤压过程中金属温度场变化和局部变形速率对管道晶粒组织演变具有重要影响。相同工艺因素条件下,平均晶粒尺寸在轴向上从变形区到挤出端逐渐递增,而在径向上从管道内侧到外侧逐渐递减;管道内侧的动态再结晶百分数高于外侧;管道金属在轴向比径向有更高的动态再结晶发生率,且动态再结晶晶粒尺寸比径向更小。管道的平均晶粒尺寸随着挤压比的增加呈减小的趋势,挤压比越大,动态再结晶发生的越充分,越利于晶粒细化。进行了与数值模拟相配套的缩比挤压成形实验,并针对获得的样件分别进行了金相实验和晶粒度评定,所测得的平均晶粒尺寸变化规律与数值模拟基本吻合,证明了数值模拟的正确性,同时验证了增大挤压比对管道晶粒细化具有重要的促进作用。
The scaling numerical simulations of the vertical forward extrusion process of a certain type of P91 large diameter and thick wall seamless pipe for nuclear energy power generation under different extrusion ratios were carried out to research the microstructure evolvement regularity in the extrusion process. The results show that the change of metal temperature field and local deformation rate in the extrusion process has important effect on the microstructure evolution of extruded pipe. Under the same process factor condition,the average grain size increases gradually from the deformation zone to the extrusion end in axial direction,and decreases gradually from the inner side to the outer side of the pipe in radial direction; the percentage of dynamic recrystallization inside the pipe is higher than that outside the pipe; the dynamic recrystallization rate of pipe material in axial direction is higher than that in radial direction,and the dynamic recrystallization grain size is smaller than that in radial direction; the average grain size of the pipe decreases with the increase of extrusion ratio; the greater the extrusion ratio is,the more sufficient the dynamic recrystallization occurs,the better the grain refinement is. The metallographic experiments and grain size evaluation were carried out for the samples obtained by scaling extrusion experiments matched with numerical simulations,it is indicated that the experimental results about average grain size variation are basically consistent with the numerical simulations,which shows the correctness of numerical simulations and verifies that increasing extrusion ratio plays an important role in promoting grain refinement.
The scaling numerical simulations of the vertical forward extrusion process of a certain type of P91 large diameter and thick wall seamless pipe for nuclear energy power generation under different extrusion ratios were carried out to research the microstructure evolvement regularity in the extrusion process. The results show that the change of metal temperature field and local deformation rate in the extrusion process has important effect on the microstructure evolution of extruded pipe. Under the same process factor condition,the average grain size increases gradually from the deformation zone to the extrusion end in axial direction,and decreases gradually from the inner side to the outer side of the pipe in radial direction; the percentage of dynamic recrystallization inside the pipe is higher than that outside the pipe; the dynamic recrystallization rate of pipe material in axial direction is higher than that in radial direction,and the dynamic recrystallization grain size is smaller than that in radial direction; the average grain size of the pipe decreases with the increase of extrusion ratio; the greater the extrusion ratio is,the more sufficient the dynamic recrystallization occurs,the better the grain refinement is. The metallographic experiments and grain size evaluation were carried out for the samples obtained by scaling extrusion experiments matched with numerical simulations,it is indicated that the experimental results about average grain size variation are basically consistent with the numerical simulations,which shows the correctness of numerical simulations and verifies that increasing extrusion ratio plays an important role in promoting grain refinement.
引文
[1]洪钟.电力在我国能源中的战略地位[J].中国经贸导刊,2014,(19):10-16.HONG Zhong.The strategic status of electric power in Chinese energy[J].China Economic&Trade Herald,2014,(19):10-16.
[2]钟宇航,黄及娟,姜兰兰.我国核电现状及发展趋势[J].华北电力大学学报(社会科学版),2014,92(6):7-10.ZHONG Yuhang,HUANG Jijuan,JIANG Lanlan.The current situation and development trend of nuclear power in China[J].Journal of North China Electric Power University(Social Sciences),2014,92(6):7-10.
[3]金雪芹,张建,毕大森.P91钢的热压缩动态组织演化数值模拟[J].锻压技术,2012,37(3):119-122.JIN Xueqin,ZHANG Jian,BI Dasen.Simulation of P91 steel dynamic microstructure evolution during hot-upsetting[J].Forging&Stamping Technology,2012,37(3):119-122.
[4]郭剑.氮含量对核电管道用316LN钢热变形组织和热塑性的影响[D].秦皇岛:燕山大学,2014.GUO Jian.Effect of nitrogen content on hot deformation microstructure and hot ductility of 316LN steels for reactor main pipe[D].Qinhuangdao:Yanshan University,2014.
[5]侯庆志,李顺达,林磊.核电厂蒸汽管道中高速运动水团冲击研究[J].核科学与工程,2019,39(1):18-23.HOU Qingzhi,LI Shunda,LIN Lei.High velocity water slug impact in steam pipelines of NPP[J].Nuclear Science and Engineering,2019,39(1):18-23.
[6]武东文,吴任东,袁朝龙,等.大口径钢管突破挤压力分析[J].塑性工程学报,2017,24(1):24-29.WU Dongwen,WU Rendong,YUAN Chaolong,et al.Analysis of breakthrough extrusion pressure for large scale steel pipe[J].Journal of Plasticity Engineering,2017,24(1):24-29.
[7]王雪凤,吴任东,邓晨曦,等.新型耐热高强钢P91的高温力学性能[J].机械工程学报,2008,44(6):243-247.WANG Xuefeng,WU Rendong,DENG Chenxi,et al.Mechanical properties of new heat-resistant high-tensile steel P91 at high temperature[J].Chinese Journal of Mechanical Engineering,2008,44(6):243-247.
[8]金雪芹.P91材料高温流动性与晶粒组织演化模型的研究[D].天津:天津理工大学,2012.JIN Xueqin.Research on flow stress behavior and microstructure evolution in high temperature of P91 steels[D].Tianjin:Tianjin University of Technology,2012.
[9]李攀,罗建国,刘航,等.整体式挂车支承桥主轴变温挤压成形工艺[J].锻压技术,2018,43(3):75-82.LI Pan,LUO Jianguo,LIU Hang,et al.Extrusion forming process with variable temperature for integral main shaft of trailer support bridge[J].Forging&Stamping Technology,2018,43(3):75-82.
[10]白箴,董霞,刘科虹.TP321奥氏体不锈钢无缝钢管垂直挤压工艺研究[J].中国重型装备,2014,(3):48-52.BAI Zhen,DONG Xia,LIU Kehong.Research on vertical extrusion process of P91 TP321 austenitic stainless steel seamless pipe[J].China Heavy Equipment,2014,(3):48-52.
[11]武东文,吴任东,袁朝龙,等.大口径钢管突破挤压力分析[J].塑性工程学报,2017,24(1):24-29.WU Dongwen,WU Rendong,YUAN Chaolong,et al.Analysis of breakthrough extrusion pressure for large scale steel pipe[J].Journal of Plasticity Engineering,2017,24(1):24-29.
[12]陈雷,裴建明,郭晓敏,等.大口径厚壁管热挤压过程中晶粒组织均匀性数值模拟[J].塑性工程学报,2017,24(4):103-109.CHEN Lei,PEI Jianming,GUO Xiaomin,et al.Numerical simulation on homogeneity of grain structure for large diameter and thick wall pipes during hot extrusion process[J].Journal of Plasticity Engineering,2017,24(4):103-109.
[13]余凯,程和法,陈文琳,等.扭力梁热成形过程温度与微观组织的研究[J].塑性工程学报,2017,24(3):109-114.YU Kai,CHENG Hefa,CHEN Wenlin,et al.Temperature and microstructure of torsion beam during hot forming[J].Journal of Plasticity Engineering,2017,24(3):109-114.
[2]钟宇航,黄及娟,姜兰兰.我国核电现状及发展趋势[J].华北电力大学学报(社会科学版),2014,92(6):7-10.ZHONG Yuhang,HUANG Jijuan,JIANG Lanlan.The current situation and development trend of nuclear power in China[J].Journal of North China Electric Power University(Social Sciences),2014,92(6):7-10.
[3]金雪芹,张建,毕大森.P91钢的热压缩动态组织演化数值模拟[J].锻压技术,2012,37(3):119-122.JIN Xueqin,ZHANG Jian,BI Dasen.Simulation of P91 steel dynamic microstructure evolution during hot-upsetting[J].Forging&Stamping Technology,2012,37(3):119-122.
[4]郭剑.氮含量对核电管道用316LN钢热变形组织和热塑性的影响[D].秦皇岛:燕山大学,2014.GUO Jian.Effect of nitrogen content on hot deformation microstructure and hot ductility of 316LN steels for reactor main pipe[D].Qinhuangdao:Yanshan University,2014.
[5]侯庆志,李顺达,林磊.核电厂蒸汽管道中高速运动水团冲击研究[J].核科学与工程,2019,39(1):18-23.HOU Qingzhi,LI Shunda,LIN Lei.High velocity water slug impact in steam pipelines of NPP[J].Nuclear Science and Engineering,2019,39(1):18-23.
[6]武东文,吴任东,袁朝龙,等.大口径钢管突破挤压力分析[J].塑性工程学报,2017,24(1):24-29.WU Dongwen,WU Rendong,YUAN Chaolong,et al.Analysis of breakthrough extrusion pressure for large scale steel pipe[J].Journal of Plasticity Engineering,2017,24(1):24-29.
[7]王雪凤,吴任东,邓晨曦,等.新型耐热高强钢P91的高温力学性能[J].机械工程学报,2008,44(6):243-247.WANG Xuefeng,WU Rendong,DENG Chenxi,et al.Mechanical properties of new heat-resistant high-tensile steel P91 at high temperature[J].Chinese Journal of Mechanical Engineering,2008,44(6):243-247.
[8]金雪芹.P91材料高温流动性与晶粒组织演化模型的研究[D].天津:天津理工大学,2012.JIN Xueqin.Research on flow stress behavior and microstructure evolution in high temperature of P91 steels[D].Tianjin:Tianjin University of Technology,2012.
[9]李攀,罗建国,刘航,等.整体式挂车支承桥主轴变温挤压成形工艺[J].锻压技术,2018,43(3):75-82.LI Pan,LUO Jianguo,LIU Hang,et al.Extrusion forming process with variable temperature for integral main shaft of trailer support bridge[J].Forging&Stamping Technology,2018,43(3):75-82.
[10]白箴,董霞,刘科虹.TP321奥氏体不锈钢无缝钢管垂直挤压工艺研究[J].中国重型装备,2014,(3):48-52.BAI Zhen,DONG Xia,LIU Kehong.Research on vertical extrusion process of P91 TP321 austenitic stainless steel seamless pipe[J].China Heavy Equipment,2014,(3):48-52.
[11]武东文,吴任东,袁朝龙,等.大口径钢管突破挤压力分析[J].塑性工程学报,2017,24(1):24-29.WU Dongwen,WU Rendong,YUAN Chaolong,et al.Analysis of breakthrough extrusion pressure for large scale steel pipe[J].Journal of Plasticity Engineering,2017,24(1):24-29.
[12]陈雷,裴建明,郭晓敏,等.大口径厚壁管热挤压过程中晶粒组织均匀性数值模拟[J].塑性工程学报,2017,24(4):103-109.CHEN Lei,PEI Jianming,GUO Xiaomin,et al.Numerical simulation on homogeneity of grain structure for large diameter and thick wall pipes during hot extrusion process[J].Journal of Plasticity Engineering,2017,24(4):103-109.
[13]余凯,程和法,陈文琳,等.扭力梁热成形过程温度与微观组织的研究[J].塑性工程学报,2017,24(3):109-114.YU Kai,CHENG Hefa,CHEN Wenlin,et al.Temperature and microstructure of torsion beam during hot forming[J].Journal of Plasticity Engineering,2017,24(3):109-114.