Oxidation of SS304 and SS316 and the formation of diffusionally isolated regions leading to localised premature breakaway oxidation

IF 1 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials at High Temperatures Pub Date : 2023-02-25 DOI:10.1080/09603409.2023.2177938

M. Taylor, J. Husband

引用次数: 1

Abstract

ABSTRACT The results are presented on the oxidation behaviour of two chromia-forming steels, over the temperature range 800°C to 900°C, regions of premature localised breakaway oxidation were observed. SiO2 formation along emergent grain boundaries encapsulated smaller grains, acting as diffusion barriers to the replenishment of chromium from deeper in the alloy. Rapid depletion of chromium from these isolated grains continued with increasing time until the concentration was insufficient to maintain a protective Cr2O3 resulting in the localised chemical failure and formation of breakaway oxides. A finite difference model was used to demonstrate the effect of SiO2 formation. It was also found that the low concentration of silicon restricted the encapsulation process to only the smaller grains at the surface and protective oxidation was re-established underneath at the alloy surface. The predicted lifetime of components with wall thicknesses of 2 mm was calculated to be in excess of 30 years.

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SS304和SS316的氧化和扩散孤立区域的形成导致局部过早分离氧化

本文研究了两种铬成形钢在800 ~ 900℃温度范围内的氧化行为，观察到过早局部分离氧化区域。沿着晶界形成的SiO2包裹了较小的晶粒，作为扩散屏障，阻止了铬从合金深处补充。随着时间的增加，铬从这些分离的颗粒中迅速耗竭，直到浓度不足以维持保护性的Cr2O3，导致局部化学失效和分离氧化物的形成。采用有限差分模型分析了SiO2地层的影响。同时发现，低浓度的硅限制了包封过程仅局限于表面较小的晶粒，并在合金表面下重新建立了保护性氧化。计算结果表明，壁厚为2mm的部件的预测寿命超过30年。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Materials at High Temperatures 工程技术-材料科学：综合

CiteScore

1.90

自引率

15.40%

发文量

审稿时长

>12 weeks

期刊介绍： Materials at High Temperatures welcomes contributions relating to high temperature applications in the energy generation, aerospace, chemical and process industries. The effects of high temperatures and extreme environments on the corrosion and oxidation, fatigue, creep, strength and wear of metallic alloys, ceramics, intermetallics, and refractory and composite materials relative to these industries are covered. Papers on the modelling of behaviour and life prediction are also welcome, provided these are validated by experimental data and explicitly linked to actual or potential applications. Contributions addressing the needs of designers and engineers (e.g. standards and codes of practice) relative to the areas of interest of this journal also fall within the scope. The term ''high temperatures'' refers to the subsequent temperatures of application and not, for example, to those of processing itself. Materials at High Temperatures publishes regular thematic issues on topics of current interest. Proposals for issues are welcomed; please contact one of the Editors with details.