Effect of quenching temperature on microstructure and mechanical properties of gear steel C64

doi:10.13251/j.issn.0254-6051.2021.04.015

Abstract

Abstract: Changes of microstructure and mechanical properties of C64 steel during quenching at different temperatures were studied by means of hardness, tensile and impact tests, and with optical microscope (OM) and scanning electron microscope (SEM). The results show that when the quenching temperature is lower than 950 ℃, the lath martensite in the microstructure of the tested steel C64 is relatively fine, but when higher than 950 ℃, the lath martensite grows dramatically. With quenching temperature increasing, the carbides dissolve gradually until dissolve almost completely at 950 ℃; the strength and hardness of the steel tend to decrease, while the elongation, percentage reduction of area and impact absorbed energy of the steel tend to increase first and then decrease and reach their maximum values at 950 ℃. The optimum quenching temperature of the tested steel is 950 ℃, at which uniform and fine lath martensite can be obtained; the tensile strength, yield strength, elongation, percentage reduction of area, and impact absorbed energy of the tested steel is respectively 1122 MPa, 1106 MPa, 11.40%, 25.20%, 191.0 J, which can offer the best match of strengthening and toughening.

Key words: gear steel, quenching temperature, microstructure, mechanical properties, fracture morphologies

CLC Number:

TG156.31

Liang Xiaodong, Ju Zhe, Liu Ji, Wang Chenchong, Wang Xu. Effect of quenching temperature on microstructure and mechanical properties of gear steel C64[J]. Heat Treatment of Metals, 2021, 46(4): 88-94.

References

[1] 周敏,厉勇,黄顺喆,等.奥氏体化温度对二次硬化渗碳钢组织与力学性能的影响[J].金属热处理,2017,42(2):108-112.
Zhou Min,Li Yong,Huang Shunzhe,et al.Effect of austenitizing temperature on microstructure and mechanical properties of secondary hardened carburized steel[J].Heat Treatment of Metals,2017,42(2):108-112.
[2] Kuehmann C J,Olson G B.Computational materials design and engineering[J].Materials Science and Technology,2009,25(4):472-478.
[3] 王昊杰,郝浩腾,王昭东,等.渗碳工艺参数对常见渗碳钢晶粒粗化行为的影响[J].材料热处理学报,2017,38(3):177-185.
Wang Haojie,Hao Haoteng,Wang Zhaodong,et al.Effect of carburizing process parameters on the grain coarsening behavior of common carburized carbon steels[J].Transactions of Materials and Heat Treatment,2017,38(3):177-185.
[4] 周凤云,李熙章.高强度渗碳钢制构件的断裂分析[J].理化检验(物理分册),2003,39(4):206-209.
Zhou Fengyun,Li Xizhang.Fracture analysis of the components made of high strength and carburizing steel[J].Physical Testing and Chemical Analysis Part A:Physical Testing,2003,39(4):206-209.
[5] 刘宝锋,杨钢,华建社,等.淬火温度对AMS 6308钢组织和性能的影响[J].特钢技术,2012,18(3):12-17.
Liu Baofeng,Yang Gang,Hua Jianshe,et al.Effect of quenching temperature on the microstructure and properties of AMS 6308 steel[J].Special Steel Technology,2012,18(3):12-17.
[6] 邓黎辉,汪宏斌,李绍宏,等.高强韧冷作模具钢深冷处理性能及组织[J].材料热处理学报,2011,32(4):76-81.
Deng Lihui,Wang Hongbin,Li Shaohong,et al.Cryogenic properties and microstructure of high strength and tough cold working die steel[J].Transactions of Materials and Heat Treatment,2011,32(4):76-81.
[7] Kern C P,Wright J A,Sebastian J T,et al.Manufacturing and processing of a new class of vacuum-carburized gear steels with very high hardenability[C]//American Gear Manufacturers Association Fall Technical Meeting 2011.2011:390-403.
[8] Morito S,Yoshida H,Maki T,et al.Effect of block size on the strength of lath martensite in low carbon steels[J].Materials Science and Engineering A,2006,438-440:237-240.
[9] Morito S,Saito H,Ogawa T,et al.Effect of austenite grain size on the morphology and crystallography of lath martensite in low carbon steels[J].ISIJ International,2005,45(1):91-94.
[10] Yuan W,Panigrahi S K,Su J Q,et al.Influence of grain size and texture on Hall-Petch relationship for a magnesium alloy[J].Scripta Materialia,2011,65(11):994-997.
[11] 王莉霞.淬火温度对20CrMnTiH钢力学性能的影响[J].热加工工艺,2017,46(22):221-224.
Wang Lixia.Effect of quenching temperature on mechanical properties of 20CrMnTiH steel[J].Hot Working Technology,2017,46(22):221-224.
[12] 钱灵锋,朱旭东,王华,等.热处理温度对轻质中锰钢组织和力学性能的影响[J].上海金属,2019,41(3):56-61.
Qian Lingfeng,Zhu Xudong,Wang Hua,et al.Effect of heat treatment temperature on microstructure and mechanical properties of light medium manganese steel[J].Shanghai Metals,2019,41(3):56-61.
[13] Babu N K,Suresh M R,Sinha P P,et al.Effect of austenitizing temperature and cooling rate on the structure and properties of a ultrahigh strength low alloy steel[J].Journal of Materials Science,2006,41(10):2971-2980.
[14] 方萍,苏杰,赵晓丽,等.奥氏体化温度对30Cr4Si2NiMoNb超高强度钢强韧性的影响[J].金属热处理,2013,38(5):88-91.
Fang Ping,Su Jie,Zhao Xiaoli,et al.Effect of austenitizing temperature on strength and toughness of 30Cr4Si2NiMoNb ultrahigh strength steel[J].Heat Treatment of Metals,2013,38(5):88-91.
[15] 陈豪,徐海峰,周天鹏,等.淬火和低温处理对X30 CrMoN 151组织性能影响[J].钢铁,2019,54(9):85-93.
Chen Hao,Xu Haifeng,Zhou Tianpeng,et al.Effect of quenching and low temperature treatment on microstructure and properties of X30 CrMoN 151[J].Iron and Steel,2019,54(9):85-93.