Steel in Translation Pub Date : 2021-09-20 , DOI: 10.3103/s0967091221050132 S. A. Zaides 1 , Pham Van Anh 1 , L. G. Klimova 1
Abstract
Cold-drawn metal has a number of undeniable advantages over the hot-rolled one. Increased hardness, high surface quality, stability of the diametrical dimension along the length of the workpiece are the basis for choosing calibrated metal as effective workpieces for the manufacturing of long parts such as shafts, axles, and rods. In some cases, such workpieces require a small amount of machining, for example, threading or making necks at the ends of a bar. The wider use of the calibrated metal is hindered by residual stresses that are formed during its manufacturing. In the first part of this article, it was proposed to use small plastic deformations to control residual stresses. By the example of a new process of surface plastic deformation, which is called orbital burnishing, the working and residual stresses in cylindrical workpieces are determined. In the second part of the article, the process of enveloping surface plastic deformation is considered, which, at high productivity, makes it possible to reduce the residual tensile stresses in the calibrated metal or form the surface layers of the workpiece compressive stress. A technique for the experimental determination of residual stresses in the volume of a body is based on layer-by-layer removal of the inner and outer layers of cylindrical samples. Influence of the main parameters of the enveloping deformation process on the components of the residual stress tensor is established. A range of relative compressions (0.1–1.0%) is revealed, at which residual compressive stresses are formed in the surface layers of the workpiece. It was found that at a relative compression of 0.5%, the maximum residual compression stresses are created. Enveloping surface deformation has a positive effect on the residual stress state and on cold-drawn metal: the residual tensile stresses can be reduced, removed, or converted into compressive ones.
中文翻译:
通过表面变形提高校准钢质量。第 2 部分:包络面变形对圆柱杆残余应力的影响
摘要
与热轧金属相比,冷拉金属具有许多不可否认的优势。更高的硬度、高表面质量、沿工件长度方向的直径尺寸稳定性是选择校准金属作为制造轴、轴和杆等长零件的有效工件的基础。在某些情况下,此类工件需要少量机加工,例如在棒材端部加工螺纹或制作颈部。校准金属的更广泛使用受到其制造过程中形成的残余应力的阻碍。在本文的第一部分中,建议使用小的塑性变形来控制残余应力。以一种新的表面塑性变形过程为例,称为轨道抛光,确定圆柱形工件的工作应力和残余应力。在文章的第二部分,考虑了包络表面塑性变形的过程,在高生产率的情况下,可以减少校准金属中的残余拉应力或形成工件表面层的压应力。一种通过实验确定物体体积中残余应力的技术基于逐层去除圆柱形样品的内层和外层。建立了包络变形过程的主要参数对残余应力张量分量的影响。揭示了一系列相对压缩 (0.1-1.0%),在此范围内,在工件的表层中形成残余压应力。发现在 0.5% 的相对压缩率下,产生最大残余压缩应力。包络面变形对残余应力状态和冷拉金属有积极影响:残余拉应力可以减少、消除或转化为压缩应力。