Please submit manuscripts in either of the following two submission systems

    ScholarOne Manuscripts

  • ScholarOne
  • 勤云稿件系统

  • 登录

Search by Issue

  • 2024 Vol.31
  • 2023 Vol.30
  • 2022 Vol.29
  • 2021 Vol.28
  • 2020 Vol.27
  • 2019 Vol.26
  • 2018 Vol.25
  • 2017 Vol.24
  • 2016 vol.23
  • 2015 vol.22
  • 2014 vol.21
  • 2013 vol.20
  • 2012 vol.19
  • 2011 vol.18
  • 2010 vol.17
  • 2009 vol.16
  • No.1
  • No.2

Supervised by Ministry of Industry and Information Technology of The People's Republic of China Sponsored by Harbin Institute of Technology Editor-in-chief Yu Zhou ISSNISSN 1005-9113 CNCN 23-1378/T

期刊网站二维码
微信公众号二维码
Related citation:Caixu Yue,Lei Zhu,Lei Feng,Jun Liu,Shengyu Hao,Guangxu Ren.Influences of Tool Wear on Residual Stress and Fatigue Life of Workpiece in Hard Cutting Process[J].Journal of Harbin Institute Of Technology(New Series),2018,25(5):61-69.DOI:10.11916/j.issn.1005-9113.17031.
【Print】   【HTML】   【PDF download】   View/Add Comment  Download reader   Close
←Previous|Next→ Back Issue    Advanced Search
This paper has been: browsed 1285times   downloaded 606times 本文二维码信息
码上扫一扫!
Shared by: Wechat More
Influences of Tool Wear on Residual Stress and Fatigue Life of Workpiece in Hard Cutting Process
Author NameAffiliation
Caixu Yue School of Mechanical & Electrical Engineering, Harbin Engineering University, Harbin 150001, China
School of Mechanical & Power Engineering, Harbin University of Science and Technology, Harbin 150080, China 
Lei Zhu School of Mechanical & Power Engineering, Harbin University of Science and Technology, Harbin 150080, China 
Lei Feng School of Mechanical & Power Engineering, Harbin University of Science and Technology, Harbin 150080, China 
Jun Liu School of Mechanical & Power Engineering, Harbin University of Science and Technology, Harbin 150080, China 
Shengyu Hao School of Mechanical & Power Engineering, Harbin University of Science and Technology, Harbin 150080, China 
Guangxu Ren School of Mechanical & Power Engineering, Harbin University of Science and Technology, Harbin 150080, China 
Abstract:
Tool wear has an important influence on the residual stress distribution on the machined surface. Also, it will influence the fatigue life of finished workpiece. In this research, the hard turning process of hardened die steel Cr12MoV was studied by using PCBN tool with considering tool wear. Based on the numerical treatment of residual stress, the dispersion and distribution curves of different tool wear were fitted, and the influence mechanism of tool wear on the residual stress distribution of machined surface was analyzed. Based on the theory of fatigue mechanics and mathematical statistics, the mathematical model for difference of stress dispersion and fatigue life was established. The rotating and bending tests were carried out on the standard parts after cutting process for the workpiece. The influence of tool wear on fatigue life was revealed by fracture surface morphology and fatigue life study. The results provide theoretical support for control of residual stress and the fatigue property of the machined surface under the actual working conditions.
Key words:  hard turning process  tool wear  surface residual stress  residual stress dispersion  fatigue life
DOI:10.11916/j.issn.1005-9113.17031
Clc Number:TG506.9
Fund:
Descriptions in Chinese:
  

硬态车削过程刀具磨损对残余应力和工件寿命的影响

岳彩旭,朱磊,冯磊,刘俊,郝胜宇,任广旭

(1. 哈尔滨工程大学 机电工程学院, 哈尔滨 150001;

2. 哈尔滨理工大学 机械与动力工程学院,哈尔滨 150080)

创新点说明:

本文主要研究淬硬钢Cr12MoV车削加工刀具磨损对加工表面残余应力和疲劳寿命的影响,研究结果为实际工况下工件已加工表面应力状态的控制和疲劳性能的控制提供了理论支持。

研究目的:

疲劳在金属零部件所有的失效形式中占有很大比例。特别是轴类零件,由于这类零件大多承受着不同的外载荷甚至多种载荷的交加,这种实际工况下的部件的意外事故多数是由于疲劳失效。由于疲劳失效给国家财产以及人身安全造成了巨大的隐患,因此有效的精确的预测与延长疲劳寿命成为制造工作者的一种使命。

残余应力是影响零部件疲劳性能最关键的因素之一,同时也是作为加工参数与表面性能中连接的桥梁。在传统的研究工作中达成的共识是残余压应力在延迟疲劳裂纹扩展与延长疲劳寿命中起着积极作用,但是没有整体的考虑残余应力的波动性与压应力分布模式在加工参数与疲劳性能中扮演的角色。

故本文主要研究硬态车削过程刀具磨损对残余应力和工件寿命的影响,研究结果为实际工况下工件已加工表面应力状态的控制和疲劳性能的控制提供了理论支持。

研究方法:

(1)采用不同磨损量的PCBN刀具,对淬硬模具钢Cr12MoV硬态车削过程展开实验研究。通过对残余应力离散度进行分析,拟合不同刀具磨损下的离散度指标与分布曲线,进而分析了刀具磨损对已加工表面残余应力分布的影响机制。

(2)结合疲劳力学与数理统计理论建立了应力离散度-疲劳寿命差异的数学模型,对切削后的标准试件进行了旋转弯曲实验研究,通过工件断口形貌和疲劳寿命的研究揭示了刀具磨损这一关键切削条件对工件疲劳寿命的影响。

(3)主要设备或仪器:大连机床厂生产的型号为CK6150的机床、株钻石公司牌号为MVJNR2020K16的PCBN刀具、加拿大PROTO公司的iXRD型X射线衍射应力测试系统和螺旋测微仪。

结果:

(1)残余应力离散度随着刀具磨损的增加而增大;同理,当刀具磨损在一定限度内,残余应力也随着刀具磨损的增加而增大,刀具磨损的增加会引起已加工表面压应力面积的增大和压应力层深度的增加;

(2)提出并建立了应力离散度-疲劳寿命差异数学模型,分析出残余应力引起应力幅值的波动与疲劳呈线性关系,通过疲劳弯曲试验验证了该模型的科学性和准确性。

(3)通过旋转弯曲疲劳断口裂纹特征分析,得到本文试件断口裂纹源区为半圆形,扩展区域类似沙滩粒;并且随着残余压应力面积增大,裂纹扩展距离增大,疲劳寿命越长。

(4)旋转弯曲疲劳实验结果表明刀具磨损量越大,疲劳寿命越长;反之,试件寿命越短。

结论:

(1)当刀具磨损在一定限度内,残余应力离散度和残余应力都随着刀具磨损的增加而增大,并且两者机理相同,主要是因为刀具磨损的增加会引起已加工表面压应力面积的增大和压应力层深度的增加;

(2)旋转弯曲疲劳试件断口的裂纹源区为半圆形,裂纹源区呈现的特点是较为光亮与平滑,这是由于其最先断裂扩展速度较为迟缓。随着旋转弯曲疲劳实验的进行,试件裂纹由裂纹源不断扩展,进而形成扩展速率较慢的裂纹扩展区,这里与裂纹扩展方向垂直的弧形线为该区域的重要标志,因为可以从其形状的变化来观察线端处所受应力的大小和组织形态。

(3)在刀具磨损在合理的范围内,当刀具磨损量增加时,使表面残余压应力面积越大,进而使得疲劳寿命越长;反之,试件寿命越短。为实际工况下工件已加工表面应力状态的控制和疲劳性能的控制提供了理论支持。

关键词:硬态车削,刀具磨损,表面残余应力,残余应力离散度,疲劳寿命

LINKS