轴类锻件拔长过程中组织均匀性控制的研究
发布时间：2018-08-10 19:10
【摘要】：锻件内部微观组织均匀性是决定锻件综合力学性能的重要因素。大型锻件的生产过程主要包括锻造和热处理等重要环节,锻造成形通常采用自由锻工艺。自由锻具有锻造工艺冗长、局部变形、不连续变形等特点,导致锻件变形和温度的不均匀,从而引起锻件内部微观组织不均匀,增大后续热处理的难度。因此,研究大型锻件在锻造过程中变形均匀性和微观组织演变规律,对提高锻件组织均匀性,为锻后热处理做准备具有重要意义。以锻态30Cr2Ni4MoV钢为研究对象,利用Gleeble-1500D热/力模拟试验机,使用双道次热压缩的方法,在变形温度为900~1000oC、应变速率为0.01~1s-1、道次间隔时间为5~60s的实验条件下,研究其高温变形时的静态再结晶行为,绘制出应力—应变曲线,并采用2%的补偿法确定了静态再结晶体积分数,讨论了不同变形参数对其静态再结晶的影响。根据实验结果,建立了锻态30Cr2Ni4MoV钢静态再结晶动力学模型和再结晶晶粒尺寸模型。利用DEFORM-3D软件,分析了上平下V型砧的拔长变形过程中,应变、温度、静态再结晶体积分数、动态再结晶体积分数以及晶粒分布规律,并结合缩比实验对模拟结果和实验结果进行比较、分析,得到当锻比在1.1~1.3、锻造温度在1050~1250℃范围内,随着锻比和锻造温度的增大,变形和晶粒的不均匀程度增加。
[Abstract]:The internal microstructure uniformity of forgings is an important factor to determine the comprehensive mechanical properties of forgings. The production process of large forgings mainly includes forging and heat treatment. Free forging has the characteristics of long forging process, local deformation and discontinuous deformation, which leads to the inhomogeneity of forging deformation and temperature, which causes the internal microstructure of forging to be uneven and increases the difficulty of subsequent heat treatment. Therefore, it is of great significance to study the deformation uniformity and microstructure evolution of large forgings in the process of forging, so as to improve the microstructure uniformity of forgings and prepare for post-forging heat treatment. Taking forged 30Cr2Ni4MoV steel as the research object, using Gleeble-1500D thermal / force simulation testing machine, the method of double pass thermal compression was used. Under the experimental conditions of deformation temperature of 900,1000oC, strain rate of 0.01g / 1s-1s and interval time of 5s / 60s, the strain rate was 0.01oC, and the interval time was 50s. The static recrystallization behavior during high temperature deformation is studied and the stress-strain curve is drawn. The integral number of the static recrystallization volume is determined by the compensation method of 2%. The influence of different deformation parameters on the static recrystallization is discussed. Based on the experimental results, the static recrystallization kinetics model and recrystallization grain size model of forged 30Cr2Ni4MoV steel were established. By using DEFORM-3D software, the strain, temperature, static recrystallization volume integral number, dynamic recrystallization volume integral number and grain distribution law during pull-out deformation of upper-flat-down V-shaped anvil are analyzed. By comparing the simulation results with the experimental results, it is found that when the forging ratio is 1.1 ~ 1.3and the forging temperature is 1050 ~ 1250 鈩，
本文编号：2175930
[Abstract]:The internal microstructure uniformity of forgings is an important factor to determine the comprehensive mechanical properties of forgings. The production process of large forgings mainly includes forging and heat treatment. Free forging has the characteristics of long forging process, local deformation and discontinuous deformation, which leads to the inhomogeneity of forging deformation and temperature, which causes the internal microstructure of forging to be uneven and increases the difficulty of subsequent heat treatment. Therefore, it is of great significance to study the deformation uniformity and microstructure evolution of large forgings in the process of forging, so as to improve the microstructure uniformity of forgings and prepare for post-forging heat treatment. Taking forged 30Cr2Ni4MoV steel as the research object, using Gleeble-1500D thermal / force simulation testing machine, the method of double pass thermal compression was used. Under the experimental conditions of deformation temperature of 900,1000oC, strain rate of 0.01g / 1s-1s and interval time of 5s / 60s, the strain rate was 0.01oC, and the interval time was 50s. The static recrystallization behavior during high temperature deformation is studied and the stress-strain curve is drawn. The integral number of the static recrystallization volume is determined by the compensation method of 2%. The influence of different deformation parameters on the static recrystallization is discussed. Based on the experimental results, the static recrystallization kinetics model and recrystallization grain size model of forged 30Cr2Ni4MoV steel were established. By using DEFORM-3D software, the strain, temperature, static recrystallization volume integral number, dynamic recrystallization volume integral number and grain distribution law during pull-out deformation of upper-flat-down V-shaped anvil are analyzed. By comparing the simulation results with the experimental results, it is found that when the forging ratio is 1.1 ~ 1.3and the forging temperature is 1050 ~ 1250 鈩，
本文编号：2175930
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