淬火回火热处理对WC-25%Co硬质合金组织与性能的影响  

Effects of Quenching and Tempering on Microstructure and Properties of WC-25%Co Cemented Carbide

作　　者：王忆民[1,2] 李锐[1,2] 曹群[2] 

机构地区：[1]硬质合金国家重点实验室,湖南株洲412000 [2]株洲硬质合金集团有限公司,湖南株洲412000

出　　处：《硬质合金》2014年第3期148-154,共7页Cemented Carbides

摘　　要：本文选用钴含量25%的WC-Co硬质合金,在1 250℃,真空条件下,对合金进行淬火,并于500℃回火,研究了淬火回火热处理对WC-25%Co硬质合金组织与性能的影响。研究结果表明,经1 250℃真空淬火并于500℃回火后,合金粘结相Co中面心立方结构α-Co的含量趋近于100%,WC平均晶粒尺寸保持不变,而WC晶粒邻接度明显减小,粘结相Co中固溶的W原子数量显著提高,裂纹的萌生和扩展受到抑制,合金的韧性获得改善。热处理后合金的矫顽磁力值和钴磁降低,合金中出现了明显的细小孔洞,其密度和硬度略微降低,但是合金抗弯强度由3 300 MPa提高至3 500 MPa。The effects of quenching and tempering on the microstructure and properties of WC-25% Co cemented carbide was analyzed. The cemented carbide was quenched in vacuum at 1 250 ℃ and then tempered at 500 ℃. The results show that after the quenching and tempering the content of face-centered cubic （FCC） a-Co in Co phase is close to 100%. The average grain size of WC phase remaines the same while the contiguity of WC grains siguifieantly decreases. The number of W atoms dissolved in Co phase remarkably increases. The initiation and propagation of cracks are suppressed, so the toughness of the alloy is improved. The eoercive force and Co magnetism decrease after the heat treatment. Meanwhile, there are obvious tiny pores in the alloy after quenching, and the density and hardness are slightly deduced. But the bending strength is improved from 3 300 MPa to 3 500 MPa.

关 键 词：淬火回火热处理 WC-25%Co硬质合金 抗弯强度 韧性 矫顽磁力 钴磁 

分 类 号：TG135.5[一般工业技术—材料科学与工程] TG156[金属学及工艺—合金]