摘要
以20Cr双相钢为研究对象,利用分离式霍普金斯杆技术,在旋转盘冲击拉伸试验机上完成了一次冲击拉伸和复元拉伸加卸载试验,研究了高应变速率下材料的动态力学性能。结果表明,20Cr双相钢是一种应变率和温度敏感材料。应变率增加,材料强度提高,屈强比增大,塑性略有降低,但流变阶段应变率强化系数基本不变。应变率对材料弹性模量不产生影响。增加双相组织中马氏体体积分数,材料强度提高,塑性降低,机械能密度先升后降。适量铁素体是20Cr双相钢获得高韧度的必要条件。
Split Hopkinson bar recovery experimental techniques were used to explore the impact tensile behavior of dual 20Cr steel. Both once impact and multiple reloaded of unloaded impact tensile experiments were carried out on a rotating circular plate impact machine. The dynamic mechanical properties of this steel at high strain rates were investigated. Experiment results exhibited that dual phase 20Cr steel showed a strong sensitivity to the strain rate and temperature. Raising the testing strain rate, the strength and yield ratio increased the plasticity slightly decreased, but the strain rate hardening index kept constant. The strain rate did not influence the modulus of elesticity. With the addition of the volume fraction of martensite, the strength was promoted, the plasticity was weekened, the mechanical energy densite first rose, then lowered. The proper amount of ferrite is one of the necessary conditions for high toughness.
出处
《机械工程材料》
CAS
CSCD
1996年第6期23-26,共4页
Materials For Mechanical Engineering
