摘要拔长过程中，大锻件心部产生拉应力，导致锻件质量不合格。在工程中通常采用 FM 锻造法、JTS 锻造法、LZ 锻造法等来避免在锻造成形过程中产生拉应力。而在 LZ 锻造法中影响拉应力产生的最主要的因素就是砧宽比和料宽比。 80625

本文通过 DEFORM-3D 软件对 LZ 锻造法工艺进行数值模拟，分析其锻件内部的应 力状态。研究不同的砧宽比和料宽比对锻件心部的应力状态的影响，并且在锻件心部 附近取点，研究他们的应力变化。通过结果分析，发现在砧宽比和料宽比都为 0。5 时， 锻件心部的最大拉应力最小，而离锻件心部越远所受到的最大拉应力就越小。通过对 锻件在整个成形过程中的应变分布进行分析，在大锻件心部两端与上下砧接触的地方 应变值最大，而心部最小。这说明两端的变形量大于心部。通过对 LZ 锻造法的数值 模拟，给拔长工艺提供了参考价值。 

毕业论文关键词：大锻件；数值模拟；LZ 法；应力分析 

Abstract In the process of pulling out, the tensile stress is produced in the core part of the large forgings, which leads to the failure of the forging quality。 In the engineering, the FM forging method, JTS forging method and LZ forging method are usually used to avoid the tensile stress in the forging process。 The main factors that affect the tensile stress in the LZ forging process are the ratio of the width to the anvil and the width of the material。

In this paper, the numerical simulation of LZ forging process is carried out by DEFORM-3D software, and the stress state in the forging process is analyzed。 The effects of different anvil width ratio and material width ratio on the stress state of the forging center are studied, and the stress changes in the vicinity of the core part of the forging are studied。 The maximum tensile stress at the core of the forging is minimum when the anvil width ratio and the material width ratio are 0。5。 And the maximum tensile stress is smaller when the center of the forging is too far away from the center of the forging。 Through the analysis of the strain distribution in the whole process of forging, the strain at both ends of the core of the large forging and the upper and lower anvil is close to the place where the strain is the most, while the heart is the smallest。 That indicates that the deformation of both ends is larger than that of the heart。 Through the numerical simulation of the LZ forging method, it provides the reference value for the drawing process。

Keywords: Heavy forging; Numerical simulation; LZ method; Stress analysis

目录

第一章 绪论 1

1。1 引言 1

1。2 大锻件在国内外的发展状况 2

1。3 大型锻件锻造工艺发展现状 3

1。4 大锻件的数值模拟 6

1。5 本文研究的意义和内容 6

第二章 DEFORM 软件 8

2。1 简介 8

2。2DEFORM 功能 9

2。3DEFORM 的软件操作流程 9

第三章 LZ 锻造法模拟 11

3。1 引言 11

3。2 材料的选择 11

3。3 有限元模型的建立 12

3。3。1 坯料和模具的导入 12

3。3。2 网格的划分 13