摘要
介绍了棒管料低应力精密下料工艺的原理及设备结构,为分析不同加工方法预制的V型槽对低应力精密下料工艺的影响,分别采用车削、铣削和激光3种开槽方法在304不锈钢厚壁无缝管上预制了相同深度的V型槽,并在低应力下料设备上开展了下料试验,得到了对应于不同开槽方法的下料时间和断面质量。试验结果表明:下料效率方面,铣削>车削>激光;断面质量方面,激光>车削>铣削。通过扫描电子显微镜对3种V型槽底部进行观察,获得了不同开槽方法下V型槽底部的表面形貌,揭示了V型槽的表面质量和热影响区对低应力下料过程中初始裂纹萌生的影响,分析了不同开槽方法时下料断面上撕裂区的产生原因。试验结果对低应力精密下料工艺开槽方法的选择具有参考价值。
The principle and equipment structure of low stress precision cutting process for rods and tubes were introduced firstly,and the same depth V-shaped grooves were preliminarily produced on 304 stainless steel thick-walled seamless pipe by turning,milling and laser manufacturing respectively in order to analyze influences of the V-groove prefabricated by different processing methods on the low-stress precision cutting process. Then,the cutting tests were conducted by low-stress cutting devices,and the cutting time and cross section quality were obtained for different slotting methods. The results show that for cuttingg efficiency,milling process > turning process > laser process,while for cross section quality,laser process > turning process > milling process. Furthermore,the bottom of three different V-shaped grooves were observed by Scanning Electron Microscope( SEM) and the bottom surface morphologies of V-shaped grooves prefabricated by different slotting methods were obtained. Furthermore the influences of surface quality and heat-effect zone of V-shaped grooves on the generating process of initial cracks in the low-stress cutting process are revealed to analyze the generating reason of tearing area in the cross section respectively. Thus,the experimental results have reference value for selecting of slotting method for low-stress precision cutting.
引文
[1]阮雪榆.冷挤压技术[M].上海:上海人民出版社,1976.Ruan X Y.Cold Extruding Technology[M].Shanghai:Shanghai People's Publishing House,1976.
[2]陈金德.金属材料精密分离概论[J].模具工业,1990,16(6):5-10.Chen J D.Introduction to precise separation of metal material[J].Die&Mould Industry,1990,16(6):5-10.
[3]Ding P D,Zhou S Z,Pan F S,et al.Ecotechnology for highspeed tool steels[J].Mechanical&Design,2001,22(2):137-142.
[4]李继威,胡成亮,赵震,等.剪切速度对棒料剪切断面质量的影响[J].锻压技术,2016,41(8):122-126.Li J W,Hu C L,Zhao Z,et al.Influence of shearing speed on section quality for bar shearing[J].Forging&Stamping Technology,2016,41(8):122-126.
[5]陈康,肖小亭,陈苑坤,等.基于机器视觉的冲裁断面质量检测[J].锻压技术,2016,41(6):109-114.Chen K,Xiao X T,Chen Y K,et al.Inspection of blanking section quality based on machine vision[J].Forging&Stamping Technology,2016,41(6):109-114.
[6]Hua C J,Zhao S D,Zhang L J,et al.Investigation on the dynamic characteristic of a new type of precision cropping system with variant frequency vibration[J].International Journal of Mechanical Sciences,2006,48(12):1333-1340.
[7]魏庆同,郎福元,芮执元,等.一种拉弯式应力断料机[P].中国:96100383.9,1997-07-23.Wei Q T,Lang F Y,Rui Z Y,et al.A kind of bending stress cutting machine[P].China:96100383.9,1997-07-23.
[8]李有堂,俞焕然.具有环形缺口圆杆在弯曲载荷下的裂断问题[J].兰州大学学报:自然科学版,1996,32(4):34-39.Li Y T,Yu H R.The broken problems of the round stem with the annular gap in bending load[J].Journal of Lanzhou University:Natural Science,1996,32(4):34-39.
[9]Hua C J,Zhao S D,Zhang L J,et al.Investigation on the dynamic characteristic of a new type of precision cropping system with variant frequency vibration[J].International Journal of Mechanical Sciences,2006,48(12):1333-1340.
[10]Zhao R F,Zhao S D,Guo J H,et al.Experimental and numerical investigation on ductile fracture mechanism of aluminum alloy using new modified model[J].Materials Science and Technology,2015,31(3):303-309.
[11]马广英,郎福元,龚俊.裂纹技术在应力下料中的研究与应用[J].甘肃科学学报,2003,15(3):86-90.Ma G Y,Lang F Y,Gong J.The investigation and application of crack technique in stress bar severing[J].Journal of Gansu Sciences,2003,15(3):86-90.
[12]张立军,赵升吨,唐勇.热应力对金属棒料内部损伤的机理研究[J].西安交通大学学报,2009,43(1):99-113.Zhang L J,Zhao S D,Tang Y.Inner damage mechanism of metal bar with thermal stress[J].Journal of Xi'an Jiaotong University,2009,43(1):99-113.
[13]Zhao R F,Zhao S D,Zhong B.Experiment study on novel precision cropping machinery using rotary striking action[J].Applied Mechanics and Materials,2013,28:287-292.
[14]Zhao S D,Zhang L J,Lei J,et al.Numerical study on heat stress prefabricating ideal crack at the bottom of V shaped notch in precision cropping[J].Journal of Materials Processing Technology,2007,187-188:363-367.
[15]Zhao R F,Zhao S D,Zhong B,et al.Experimental investigation on new low cycle fatigue precision cropping process[J].Proceedings of the Institution of Mechanical Engineers,Part C:Journal of Mechanical Engineering Science,2015,229(8):1470-1476.
[16]赵升吨,崔敏超,陈超,等.一种对称多刀的棒管料开槽机[P].中国:0193035.1,2014-05-08.Zhao S D,Cui M C,Chen C,et al.A symmetrical multi-tool rod tube slot machine[P].China:0193035.1,2014-05-08.