权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of High Temperature Stress-Strain Test for Multi-Layred Materials

多层材料高温应力应变测试的发展

基本信息

批准号：
06555219
负责人：
EMI Toshihiko
金额：
$ 12.99万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06555219/
关键词：
multi-layred materials hot tensile test temperature gradient field solidified steel shell peritectic medium carbon steel continuous casting longitudinal facial crack critical strain for crack formation 鋼引張試験曲げ試験割れ限界歪み量界面熱抵抗 δ

项目摘要

In present study, convenient and simple temperature gradient tensile and bending tests were developed with which mechanical properties of materials which exhibit multi-layr structure under temperature gradient, e.g., steels in casting mold and the critical strain for the crack formation can be determined at better accuracy with rectangular test-pieces.(1) Results of present tests agree well with those by thermal elastic plastic stress analysis where finite element code is employed with corresponding stress-strain data measured in isothermal temperature field at different temperatures. The present tests can replace, therefore, the troublesome tensile tests as well as the complicated thermal elastic plastic stress analysis, and capable of determining mechanical properties of multi-layred materials (or materials under temperature gradient) reliably by one test.(2) The fracture strength of solidifying steel shells determined by the temperature gradient test agrees well with that by a subme … More rged split chill tensile test to measure in-situ the fracture strength of solidifying steel shells. The fracture strength of ultra low and low carbon steel shells with thinner thickness is lower than that of medium and high carbon steels.(3) Internal cracks were found to form at the hot side of test-piece during straining. The critical strain was independent of test methods, measured from 0.6% to 2.1% and decreased with increasing carbon content and grain boundary segregation. Surface cracks arising in high speed casting of peritectic medium carbon (0.09-0.16mass%C) steel slabs is not caused by low fracture strength of the steels. A cause of cracking for these steels is, therefore, considered that the shell deformation occurs as a consequence of shell shrinkage due to delta/gamma transformation during initial solidification. The shrinkage induces surface roughness of the shell, resulting in anomalous decrease of heat transfer from the shell to mold, often causing uneven shell growth and surface cracks on the shell. Less

本研究开发了简便的温度梯度拉伸和弯曲试验，用于研究具有多层结构的材料在温度梯度作用下的力学性能，用矩形试件可以较准确地测定铸型中的钢的应变和裂纹形成的临界应变。(1)试验结果与有限元热弹塑性应力分析结果吻合较好，并给出了不同温度下等温温度场的应力-应变实测数据。因此，本试验可代替繁琐的拉伸试验和复杂的热弹塑性应力分析，并能用一次试验可靠地测定多层材料（或温度梯度下的材料）的力学性能。(2)用温度梯度法测定的凝固钢壳的断裂强度与用亚稳态法测定的断裂强度符合得很好 ...更多信息分段冷裂拉伸试验，以现场测量凝固钢壳的断裂强度。厚度较薄的超低碳钢和低碳钢壳体的断裂强度低于中碳钢和高碳钢。(3)在应变过程中，发现试样热侧产生内部裂纹。临界应变是独立的测试方法，从0.6%到2.1%，并随着碳含量和晶界偏析的增加而降低。高速铸造中碳（0.09-0.16mass%C）钢板坯表面裂纹的产生不是由于钢的断裂强度低所致。因此，这些钢开裂的原因被认为是由于在初始凝固期间的δ/γ转变导致的壳收缩而发生壳变形。收缩导致型壳表面粗糙，导致从型壳到模具的传热异常减少，通常导致型壳生长不均匀和型壳上的表面裂纹。少