球铁凸轮轴等温淬火工艺研究

研究了等温温度和等温时间对球铁凸轮轴力学性能的影响。结果显示:(1)抗拉强度随凸轮轴等温温度的升高而降低,伸长率先升高后降低,约在380℃达到最大值;抗拉强度随着等温时间的延长而升高,伸长率先升高后降低,约在3h达到最大值。(2)本试验条件下,球铁凸轮轴合适的等温淬火工艺为:900℃×1h+380℃×3h,此工艺下得到的球铁凸轮轴抗拉强度高于900MPa,伸长率高于7%,满足使用要求。

An Investigation on Isothermal Quenching Process of Nodular Iron Camshaft

The influences of isothermal quenching temperature and isothermal holding duration on mechanical properties of the nodular iron camshaft were investigated. The results showed： a） with increase of the iso-quenching temperature the tensile strength was decreased, the elongation was increased at first, and then was reduced, and reached its maximum value at about 380 ℃; with lengthening of the isothermal holding duration, the tensile strength was increased, the elongation was increased at first and then reduced, and reached its maximum value at about 3 h; b） under the current test condition, the appropriate isothermal quenching process for the camshaft was as follows： 900 ℃×1 h＋380 ℃×3 h.By adopting this process, the tensile strength of the nodular iron camshaft was higher than 900 MPa, and its elongation was higher than 7% that has met the application requirements.