【摘要】 通过降低合金元素的含量设计一种低成本低合金中碳钢，研究了不同热处理工艺下的力学性能。通过控制总应变幅，对中碳钢的低周疲劳行为进行了探究。结果表明，在302℃盐浴淬火保温2 h后试验钢具有相对较高的抗拉强度，为957 MPa。随着盐浴淬火温度升高至312℃,抗拉强度下降，U型缺口冲击性能增加；再继续升高盐浴温度，冲击性能下降。随着盐浴保温时间的增加，试验钢的硬度呈下降趋势。高应变幅(0.80%)条件下，312℃盐浴淬火试验钢的初始硬化率较低；而302℃盐浴淬火具有较高强度马氏体的试验钢具有更高的低周抗疲劳强度和疲劳寿命。更多还原

【Abstract】 A low-cost low alloy medium-carbon steel was produced, and its mechanical properties were investigated. The low-cycle fatigue behavior of the tested steel was investigated by controlling the total strain amplitude. The results show that the tested steel salt bath quenched at 302 ℃ for 2 h has a relatively high tensile strength of 957 MPa. As the salt bath quenching temperature increases to 312 ℃, the tensile strength decreases, but the U-notched impact property increases, with the salt bath temperature further increasing, the impact property is reduced. The increase of salt bath holding time results in the decrease of hardness of the tested steel. Under high strain amplitude(0.80%), the initial hardening rate of the steel salt bath quenched at 312 ℃ is lower, while the tested steel with higher strength martensite salt bath quenched at 302 ℃ has higher low-cycle fatigue strength and fatigue life.更多还原