|
|
|
| Drilling-ability Evaluation for Grey Cast Iron and Ductile Iron Front Brackets |
| REN Feng-zhang1,2,CUI Lin-kai1,3,SHI Wen-ping1,XIONG Yi1,WEI Shi-zhong1 |
1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang, Henan 471023, China
2. Henan Collaborative Innovation Centre of Non-Ferrous Generic Technology, Luoyang, Henan 471023, China
3. Third Assembly Plant, China First Tractor Group Co. Ltd., Luoyang, Henan 471004, China |
|
|
|
|
Abstract The drilling-ability of HT250 and QT450 used in front brackets of tractors has been evaluated in terms of thermal conductivity, chip shape, surface roughness in the drill hole, temperature of drill top and drilling load (torque, feeding force). The relationship between the drilling-ability and microstructure is analyzed. Experimental results show that drilling load of two front brackets was roughly same. Compared with the HT250 tractor front bracket, the one of QT450 has a larger surface roughness in the drill hole and a higher temperature of drill top. This is mainly because QT450 has a weaker graphite segmentation effect to matrix and a higher ferrite content, there is certain difficulty in chip breaking and chip removal during drilling, which leads to the larger surface roughness in the drill hole of QT450. The smaller heat conductivity coefficient and severer friction between the drill and chip result in the higher temperature of drill top. Moreover, QT450 has a smaller cutting force and a larger friction force between the drill and chip. Under the comprehensive function of the two forces, QT450 has nearly the same drilling load as HT250.
|
|
Received: 02 September 2017
Published: 06 November 2018
|
|
|
|
|
|
［1］王宇飞, 任凤章, 张旦闻, 等. 车削测量仪在机标定装置及标定方法［J］. 计量学报, 2015, 36(6): 603-606.
［2］李宗亮, 任凤章, 熊毅, 等. 蠕化剂、炉料对蠕墨铸铁组织、力学性能和切削力的影响［J］. 材料热处理学报, 2017, 38(8): 96-101.
［3］黄胜操, 任凤章, 王宇飞, 等. 合金元素Cr对灰铸铁组织性能的影响［J］. 铸造技术, 2013, 34(4): 406-408.
［4］黄胜操, 任凤章, 王宇飞, 等. 不同孕育剂处理的高强度灰铸铁加工性能研究［J］. 铸造, 2012, 61(6): 598-603.
［5］郑冰, 任凤章, 李锋军, 等. Sn对蠕墨铸铁显微组织和切削加工性能的影响［J］. 铸造, 2016, 65(2): 137-140.
［6］郑冰, 任凤章, 李锋军, 等. 不同孕育剂对蠕墨铸铁显微组织和切削加工性能的影响［J］. 铸造技术, 2016, 37(8): 1659-1662.
［7］Rosa S D N, Diniz A E, Andrade C L F, et al. Analysis of tool wear, surface roughness and cutting power in the turning process of compact graphite irons with different titanium content［J］. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2010, 32(3):234-240.
［8］Nayyar V, Kaminski J, Kinnander A, et al. An experimental investigation of machinability of graphitic cast iron grades; Flake, compacted and spheroidal graphite iron in continuous machining operations［J］. Procedia Cirp, 2012, 1(7): 488-493.
［9］Nayyar V, Grenmyr G, Kaminski J, et al. Machinability of compacted graphite iron and flake graphite iron with coated carbide［J］. International Journal of Machining and Machinability of Materials, 2013, 13(1): 67-90.
［10］Ren F Z, Li F J, Liu W M, et al. Effect of inoculating addition on machinability of gray cast Iron［J］. Journal of Rare Earths, 2009, 27(2): 294-299.
［11］朱立峰, 梁嵬. 石墨个数对高强度灰铸铁切削加工性能的影响机制［J］. 长春理工大学学报(自然科学版), 2012, 35(3): 72-74.
［12］李宗亮, 任凤章, 王冰洋, 等. 不同抗拉强度铸铁的切削性能对比［J］. 河南科技大学学报(自然科学版), 2016, 37(3): 6-9. |
|
|
|
2018, Vol. 39 
