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摘要: 粉末锻造(粉锻)技术结合了粉末冶金技术和精密锻造技术的优点, 对烧结的预压件进行一次锻打即可生产出精度高、力学性能强的近净成形产品。本文选择一款齿轮材料(Q61), 通过压制、脱脂、烧结工艺获得标准块预压件, 然后进行闭模热锻获得致密的标准块。对标准块进行物理性能(密度、硬度、拉伸性能、疲劳性能等)测试和微观组织表征。结果表明, 获得的Q61粉锻标准块基本完全致密, 密度为7.87 g·cm-3; 空冷硬度约为HRC 25.3, 淬火硬度约为HRC 62.1, 空冷态较低的硬度为零件后续机加工、整形提供了保证, 后续淬火获得的高硬度可节省渗碳工序; 标准块抗拉强度达到1052.8 MPa, 可与常用齿轮钢性能媲美。本文采用粉锻技术, 成功制备出高质量行星直齿轮, 其齿部高频淬火后硬度与渗碳齿轮的硬度相当。该工作为粉末锻造技术在我国工业界的发展提供了有益的探索。Abstract: Combining the advantages of powder metallurgy and precise forging technology, the powder forging (PF) technique can produce the nearly net-shaped products with the high precision and the outstanding mechanical properties efficiently. In this study, the preformed compact was processed by compacting, degreasing, and sintering, using a kind of gear material (Q61) as raw material, and finally the dense standard blocks was obtained by closed mold hot forging. The microstructure and physical properties of Q61 powder-forged blocks were characterized, including density, hardness, tensile properties, and fatigue properties. The results indicate that, the full densification blocks are prepared with the density of 7.87 g·cm-3. The Rockwell hardness of the air-cooled block is HRC 25.3, which is capable for machining and shaping; while the quenched block shows the high hardness with HRC 62.1, which can omit the conventional carburizing process. The tensile strength of the standard blocks is 1052.8 MPa, which can match those of common gear steels. Then, the planetary spur gears are processed by powder forging, and the gear teeth by high-frequency quenching shows the equivalent hardness as that of carburizing gear. This is an exploratory study for the development of powder forged technique in China.
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Key words:
- powder forging /
- gear /
- microstructure /
- physical properties
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图 2 Q61标准块烧结态（a）和锻态（b）未腐蚀光学金相图
Figure 2. Optical metallographic (OM) images of polished and un-etched samples of sintered (a) and forged (b) blocks
图 4 经空冷标准块心部位置（a）和边缘位置（b）显微组织及晶粒尺寸分布
Figure 4. Microstructure and grain size distribution of the air-cooled blocks in core area (a) and edge area (b)
图 5 经淬火标准块心部位置（a）和边缘位置（b）显微组织
Figure 5. Microstructure of the quenched blocks in core area (a) and edge area (b)
图 7 Q61粉锻标准块与常用齿轮钢的拉伸性能对比
Figure 7. Comparison of tensile properties between Q61 PF blocks and common gear steels
图 8 Q61空冷态标准块未喷丸（a）及喷丸（b）试样疲劳升降图
Figure 8. Fatigue diagram by staircase method of Q61 PF blocks: (a) untreated samples; (b) shot-peening samples
图 9 未喷丸（a）及喷丸（b）试样疲劳断口（圆圈内为疲劳源位置）
Figure 9. Fatigue fracture images of untreated samples (a) and shot-peening samples (b) (the crack initiation areas in the circles)
图 11 局部感应加热淬火齿轮淬火区（a）、交界区（b）和空冷区（c）显微组织
Figure 11. Microstructure of local induction heating hardened gear: (a) the quenched area; (b) the junction area; (c) the air-cooled area
表 1 Q61合金粉末化学成分（质量分数）
Table 1. Chemical composition of Q61 alloy powders %
Cu C O S Mn Mo Ni Fe 1.00 0.60 0.08 0.0072 0.219 0.552 1.756 余量 
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表 2 Q61空冷态标准块未喷丸及喷丸试样疲劳升降图数据分析
Table 2. Data analysis on the fatigue diagram by staircase method of Q61 PF blocks
试样状态 Si i fi ifi i2fi 未喷丸 350 2 2 4 8 340 1 3 3 3 330 0 1 0 0 总和 — 6 7 11 喷丸 340 2 5 10 20 330 1 1 1 1 320 0 1 0 0 总和 — 7 11 21 注：Si为失效试样应力水平；i为应力水平数；fi为失效事件数。
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[1] Jin R Z. Gear Heat Treatment Manual. Beijing: China Machine Press, 2015金荣植. 齿轮热处理手册. 北京: 机械工业出版社, 2015 [2] Huang P Y. Theory of Power Metallurgy. 2nd Ed. Beijing: Metallurgical Industry Press, 2004黄培云. 粉末冶金原理. 2版. 北京: 冶金工业出版社, 2004 [3] Bai L N, Liu F P, Wang S, et al. Microstructure and mechanical properties of Fe-C-Cu powder-forged connecting rod. Acta Metall Sinica, 2016, 52(1): 41 https://www.cnki.com.cn/Article/CJFDTOTAL-JSXB201601006.htm柏琳娜, 刘福平, 王邃, 等. Fe-C-Cu粉末锻造汽车发动机连杆的组织与力学性能. 金属学报, 2016, 52(1): 41 https://www.cnki.com.cn/Article/CJFDTOTAL-JSXB201601006.htm [4] Feng S C, Wang Y H, Ding R F. Application and prospect powder metallurgy in steel enterprises. Powder Metall Technol, 2015, 33(4): 296 doi: 10.3969/j.issn.1001-3784.2015.04.011冯士超, 王艳红, 丁瑞锋. 粉末冶金在钢铁企业的应用及发展前景. 粉末冶金技术, 2015, 33(4): 296 doi: 10.3969/j.issn.1001-3784.2015.04.011 [5] Boreczky E, Han F L. North America's PM industry: The challenges of an evolving automotive market. Powder Metall Technol, 2015, 33(3): 232 doi: 10.3969/j.issn.1001-3784.2015.03.014Boreczky Eric, 韩凤麟. 北美粉末冶金汽车零件产业的发展与前景. 粉末冶金技术, 2015, 33(3): 232 doi: 10.3969/j.issn.1001-3784.2015.03.014 [6] Alven D A, Imbrogno P G. The effect of density on the bending fatigue of powdered metal gears//American Society of Mechanical Engineers. Las Vegas, 2007: 879 http://proceedings.asmedigitalcollection.asme.org/pdfaccess.ashx?ResourceID=5286082&PDFSource=13 [7] Sonti N, Rao S, Anderson G. Bending fatigue, impact and pitting resistance of ausform finished P/M gears//American Gear Manufacturers Association. Alexandria, 2009: 168 http://www.researchgate.net/publication/289142038_Bending_fatigue_impact_and_pitting_resistance_of_ausform_finished_PM_gears [8] Sonti N, Rao S, Anderson G. Surface durability of ausform finished P/M gears//Advances in Powder Metallurgy&Particulate Materials. Las Vegas, 2009: 1 [9] Guo B, Ge C C, Zhang S C, et al. Powder forging technology and its application progress. Powder Metall Ind, 2011, 21(3): 45 https://www.cnki.com.cn/Article/CJFDTOTAL-FMYG201103015.htm郭彪, 葛昌纯, 张随财, 等. 粉末锻造技术与应用进展. 粉末冶金工业, 2011, 21(3): 45 https://www.cnki.com.cn/Article/CJFDTOTAL-FMYG201103015.htm [10] Wang C L. Development process of powder forged automotive planetary gears//The 20th Anniversary Corpus of PM Branch of SCS. Beijing, 2010: 104王崇琳. 粉末锻造汽车行星齿轮的研制历程//粉末冶金产业技术创新战略联盟论坛暨中国钢协机械粉末冶金协会二十周年纪念文集. 北京, 2010: 104 [11] Guo B, Ge C C, Yan Y N, et al. Simulation and analysis of compaction mechanism and influencing factors in powder compacting process. Mater Rev, 2012, 26(14): 141 https://www.cnki.com.cn/Article/CJFDTOTAL-CLDB201214040.htm郭彪, 葛昌纯, 颜永年, 等. 金属粉末压制成形机理及影响因素模拟分析. 材料导报, 2012, 26(14): 141 https://www.cnki.com.cn/Article/CJFDTOTAL-CLDB201214040.htm [12] Guo B, Ge C C, Yan Y N, et al. Simulation and analysis on effect of pressing processes and height-diameter ratio on densification of metal powder. Hot Work Technol, 2012, 41(18): 64 https://www.cnki.com.cn/Article/CJFDTOTAL-SJGY201218020.htm郭彪, 葛昌纯, 颜永年, 等. 压制工艺及压坯高径比对金属粉末致密化成形影响的模拟. 热加工工艺, 2012, 41(18): 64 https://www.cnki.com.cn/Article/CJFDTOTAL-SJGY201218020.htm [13] Guo B. Study on Powder Forging and Densification Forming Technology of Ferrous Alloy[Dissertation]. Chengdu: Southwest Jiaotong University, 2012郭彪. 铁基材料粉末锻造及致密化成形技术研究[学位论文]. 成都: 西南交通大学, 2012 [14] Wang S, Wang Q, Wang H L, et al. Effects of copper content on microstructure and mechanical properties of powder-forged rod Fe-C-Cu alloys manufactured at elevated temperature. Mater Sci Eng A, 2019, 743: 197 http://www.sciencedirect.com/science/article/pii/S0921509318316083 [15] Ji Z S. Research process and new technology of magnesium alloy in Japan. Chin J Nonferrous Met, 2004, 14(12): 1977 https://www.cnki.com.cn/Article/CJFDTOTAL-ZYXZ200412001.htm吉泽升. 日本镁合金研究进展及新技术. 中国有色金属学报, 2004, 14(12): 1977 https://www.cnki.com.cn/Article/CJFDTOTAL-ZYXZ200412001.htm [16] Hu G L, Xie X W. Heat Treatment of Steel (Principle and Process). 3rd Ed. Xi'an: Northwestern Polytechnical University Press, 2010胡光立, 谢希文. 钢的热处理(原理和工艺). 3版. 西安: 西北工业大学出版社, 2010 [17] Feng Y. Metal Material Science. Beijing: National Defense Industry Press, 2011凤仪. 金属材料学. 北京: 国防工业出版社, 2011 [18] Engström U, Han F L. Copper in P/M steels. Powder Metall Technol, 2012, 30(6): 460 https://www.cnki.com.cn/Article/CJFDTOTAL-FMYJ201206012.htmEngström Ulf, 韩凤麟. 粉末冶金钢中的Cu. 粉末冶金技术, 2012, 30(6): 460 https://www.cnki.com.cn/Article/CJFDTOTAL-FMYJ201206012.htm [19] Wang Z Y, Xing Z G, Wang H D, et al. Research status of test method for bending fatigue life of heavy duty gear. Mater Rev, 2018, 32(17): 3051 https://www.cnki.com.cn/Article/CJFDTOTAL-CLDB201817018.htm王志远, 邢志国, 王海斗, 等. 重载齿轮弯曲疲劳寿命测试方法研究现状. 材料导报, 2018, 32(17): 3051 https://www.cnki.com.cn/Article/CJFDTOTAL-CLDB201817018.htm -
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