回火工艺对SDP1Cu塑料模具钢组织与力学性能的影响

doi:10.13251/j.issn.0254-6051.2025.05.028

摘要/Abstract

摘要： 利用扫描电镜、透射电镜和洛氏硬度计,研究了回火温度和时间对不同淬火基体组织的SDP1Cu钢组织和力学性能的影响。结果表明,在回火过程中,随着回火温度从350 ℃升高到600 ℃,马氏体淬火组织钢的硬度从42.50 HRC(350 ℃×1 h)下降到32.00 HRC(600 ℃×1 h),回火温度超过550 ℃,随着回火时间的延长,硬度急剧下降;回火温度从350 ℃升高到600 ℃,贝氏体淬火组织钢的硬度先上升后下降,在475 ℃回火2 h时达到硬度峰值39.50 HRC;回火温度选择500 ℃,回火2~20 h可以使两种淬火组织的硬度差值降低到±0.5 HRC,获得良好的硬度均匀性。马氏体组织钢以回火软化为主,主要变化为板条回复、碳化物析出;贝氏体组织钢的组织演化以析出强化为主,主要发生M/A岛的分解、M₂₃C₆型碳化物的析出和富铜相的析出。

关键词: 塑料模具钢, SDP1Cu钢, 回火, 马氏体, 贝氏体, 硬度均匀性

Abstract: Effects of tempering temperature and time on the microstructure and mechanical properties of the SDP1Cu steel with different quenched substrate structures were studied by means of scanning electron microscope, transmission electron microscope, and Rockwell hardness tester. The results show that during the tempering process, when the tempering temperature increases from 350 ℃ to 600 ℃, the hardness of the steel with martensite quenched structure decreases from 42.50 HRC(350 ℃×1 h) to 32.00 HRC(600 ℃×1 h), and when the tempering temperature exceeds 550 ℃, the hardness decreases sharply with the extension of tempering time. When the tempering temperature increases from 350 ℃ to 600 ℃, the hardness of the steel with bainite quenched structure increases first and then decreases, and reaches the peak hardness of 39.50 HRC when tempered at 475 ℃ for 2 h. The tempering temperature of 500 ℃ and tempering time of 2-20 h can reduce the hardness difference between the two quenched structures to ±0.50 HRC, and obtain optimal hardness uniformity. The microstructure evolution of the steel with martensite is dominated by tempering softening mechanism, and the main changes are lath recovery and carbide precipitation. The microstructure evolution of the steel with bainite is dominated by precipitation strengthening mechanism, mainly involving the decomposition of M/A islands, the precipitation of M₂₃C₆ carbides and copper-rich phases.

Key words: plastic die steel, SDP1Cu steel, tempering, martensite, bainite, hardness uniformity

中图分类号:

TG142.1

陈旋, 符蓉, 宗林, 吴明辉, 冒新国, 李欣欣, 翟庆华, 何西娟. 回火工艺对SDP1Cu塑料模具钢组织与力学性能的影响[J]. 金属热处理, 2025, 50(5): 181-188.

Chen Xuan, Fu Rong, Zong Lin, Wu Minghui, Mao Xinguo, Li Xinxin, Zhai Qinghua, He Xijuan. Effect of tempering process on microstructure and mechanical properties of SDP1Cu plastic die steel[J]. Heat Treatment of Metals, 2025, 50(5): 181-188.

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