• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Predicting residual stresses and dimensional changes in thermally and mechanically processed ferrous alloys.
【24h】

Predicting residual stresses and dimensional changes in thermally and mechanically processed ferrous alloys.

机译：预测热和机械加工的铁合金中的残余应力和尺寸变化。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A linear-elastic finite element model was used to predict residual stresses and dimensional changes in cylindrical specimens made from multiphase ferrous alloys. The alloys were processed using thermal and mechanical deformation techniques to impart both microstructural phase transformations and plastic strain via slip and twinning. X-ray diffraction was used to validate the residual stress predictions. An initial strain determined from characterized microstructural information was used to calculate a nodal load vector for each element in the finite element model. Dimensions were estimated within 1μm of the actual value in the binary alloy.; X-ray diffraction was also used to measure the relative volume fractions of face-centered or body-centered cubic iron, and the interstitial carbon content of each phase. This data contributed to the initial strain. The other component of the initial strain came from the plastic strain, measured by characterizing the relative displacement of the boundary of press-fit pin and bulk material following deformation processing.; Processing ferrous alloys for wear and fatigue resistance can result in gradients of plastic strain, interstitial carbon content, and fractions of individual constituents through the material. The local specific volume of a microstructure is a function of the carbon, and amount of each phase at that location in the material. Gradients of specific volume and plastic strain create both local and bulk residual stresses in the material because of the enforcement of compatibility and static force equilibrium.; The specific volume of face-centered or body-centered cubic iron can be defined as a function of carbon content. Microstructures including ferrite and iron carbide or tempered martensite also have defined specific volumes. Changes in the specific volume can be used to calculate dimensional changes resulting from thermal and/or mechanical processing. These dimensional changes, along with plastic strains, can be used as initial strains to predict the final dimensions and residual stress distributions of a specified geometry, using appropriate boundary conditions and stress and strain relationship.; In addition to the average stress in each phase, micromechanics relationships were used with the x-ray data to calculate residual shear stresses. Plastic deformation resulting from high-frequency induction heating and quenching was also evaluated.
机译：线性弹性有限元模型用于预测由多相铁合金制成的圆柱形试样的残余应力和尺寸变化。使用热变形和机械变形技术对合金进行加工，以通过滑移和孪晶赋予微观结构相变和塑性应变。 X射线衍射用于验证残余应力的预测。根据表征的微结构信息确定的初始应变用于计算有限元模型中每个元素的节点载荷矢量。估计尺寸在二元合金实际值的1μm以内。 X射线衍射还用于测量面心或体心立方铁的相对体积分数，以及各相的间隙碳含量。该数据有助于初始应变。初始应变的另一部分来自塑性应变，该塑性应变是通过表征压入配合销和块状材料变形处理后边界的相对位移来测量的。处理耐磨性和抗疲劳性的铁合金会导致塑性应变，间隙碳含量以及贯穿材料的单个成分的分数发生梯度。微观结构的局部比容是碳以及材料中该位置上每个相的量的函数。由于相容性和静力平衡的增强，比容和塑性应变的梯度会在材料中产生局部和整体残余应力。面心或体心立方铁的比容可以定义为碳含量的函数。包括铁素体和碳化铁或回火马氏体在内的微观结构也具有确定的比容。比容的变化可用于计算由热和/或机械加工引起的尺寸变化。这些尺寸变化以及塑性应变可以用作初始应变，以使用适当的边界条件以及应力和应变关系来预测指定几何形状的最终尺寸和残余应力分布。除了每个阶段的平均应力外，微力学关系还与X射线数据一起用于计算残余切应力。还评估了高频感应加热和淬火引起的塑性变形。

著录项

  • 作者

    Delbrugge, Vincent.;

  • 作者单位

    The Pennsylvania State University.;

  • 授予单位 The Pennsylvania State University.;
  • 学科 Engineering Mechanical.; Engineering Metallurgy.; Engineering Materials Science.
  • 学位 Ph.D.
  • 年度 1999
  • 页码 161 p.
  • 总页数 161
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 机械、仪表工业;冶金工业;工程材料学;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号