摘要
调研测试了国内外焊接机床结构件的残余应力,试制了某立式加工中心用焊接床身、立柱和滑鞍并跟踪测试其焊接后与组合时效处理后的应力与变形。结果表明:焊接机床结构件普遍存在较大的残余应力、大多在100 MPa以上;所试制焊接床身、立柱、床身和滑鞍的焊接后初始残余应力最大分别达到154.9 MPa、274.4 MPa和300.6 MPa,接近或超过材料屈服强度,容易引起较大的变形。此外,立柱导轨、床身和滑鞍最大变形量也分别达到1.22 mm、2.24 mm、2.88 mm;经过"焊接后-热时效-半精加工-振动时效-精加工"的组合时效处理后,床身、滑鞍和立柱的应力与变形均显著降低,最大残余应力分别降低至18.1 MPa、39.8 MPa和41.9 MPa,均低于10%R_(m),最大直线度分别为19.17μm、23.57μm和36.69μm;时隔约6个月之后,导轨面的变形量控制在1μm/1000 mm~3μm/1000 mm,具有良好的精度保持性,焊接结构件可以用于精度要求高的数控金切机床和齿轮箱等的加工场所。
The residual stress of structural parts of welding machine tools at home and abroad was investigated.The welding bed,column and sliding saddle used in a vertical machining center were manufactured.And the tracking measurement of residual stress and deformation after welding and combined aging treatment were carried out.The results indicated that a large residual stress existed in the structural parts of welding machine tools which was over than 100 MPa.After welded,the maximum initial residual stress of the column,bed and sliding saddle reached 154.9 MPa,274.4 MPa and 300.6 MPa,respectively.The maximum residual stress of the column guide rail,sliding saddle and bed respectively reached 1.22 mm,2.24 mm and 2.88 mm,which approaching or exceeding yield strength of materials so that easily caused large deformation.Through the combined aging treatment of"post-welding-thermal aging-semi-finishing-vibration aging-finishing",the stress and deformation of the welding bed,sliding saddle and column are significantly reduced,the maximum residual stress respectively is reduced to 41.9 MPa,39.8 MPa and 18.1 MPa,which all lower than 10%Rm,and the maximum straightness respectively is 36.69μm,23.57μm and 19.17μm.After about six months,the deformation of the guide surface is 1μm/1000 mm~3μm/1000 mm,which means good accuracy retention.The welding structure can be used for high precision CNC gold cutting machine tools and gear boxes.
作者
卫东海
李克锐
匡毅
程鹏
WEI DongHai;LI KeRui;KUANG Yi;CHENG Peng(Zhengzhou Research Institute of Machanical Engineering Co.,Ltd.,Zhengzhou 450001,China;China Academy of Machinery Science and Technology Group Co.,Ltd.,Beijing 100044,China)
出处
《机械强度》
CAS
CSCD
北大核心
2021年第5期1170-1176,共7页
Journal of Mechanical Strength
基金
国家科技重大专项(2017ZX04012001)资助。
关键词
焊接床身
残余应力
直线度
时效处理
Welding lathe body
Residual stress
Precision
Aging treatment
