Influence of solution state and microstructure on the thermal and electrical conductivity of tool steels

固溶状态和显微组织对工具钢导热性和导电性的影响

• 批准号: 202401771
• 负责人: Professor Dr.-Ing. Werner Theisen
• 金额: --
• 依托单位: Lehrstuhl Werkstofftechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/202401771?language=en
• 关键词: Influence; solution; state; microstructure; thermal

Cold forming and hot forming are major applications of tool steels, for example in the scope of sheet forming and forging. Usually, development and selection of these steels consider technical aspects like tensile and compression strength or wear- and corrosion resistance, while physical properties like thermal and electrical conductivity are little-noticed. In the previous funding period, the influence of chemical composition and heat treatment condition on the conductivity of selected tool steels was analysed. The obtained results lead to the conclusion, that the solution state created with a heat treatment has a high impact on the thermal conductivity of tool steels, especially through the formation and solution of carbides. In the next step, the relation between carbide formation and conductivity has been investigated. Accordingly, the formation and coarsening of carbides, especially chrome-rich carbides, cause a considerably increased conductivity, decreasing the content of conductivity reducing alloying elements solved in the matrix. Additionally, basic principles of conduction in a copper infiltrated tool steel were investigated. These materials are capable of combining a high conductivity with good compression strength. During infiltration, the copper is impurified by iron, strongly reducing its conductivity. A well-directed heat treatment was found to be capable to reverse this effect to some extent.In the submitted research project, the gained findings are to be transferred to the technical application of press hardening. To accomplish this, instrumented hot forming experiments with in-tool quenching shall take place. The used tools will have a conductivity tuned by heat treatment, enabling the correlation of tool conductivity with the produced parts mechanical properties. Especially, partial heat treatment of tools and functional infiltrated layers added to the tools are to be investigated. Due to the locally adjusted heat conductivity of the tools, the produced parts can obtain graded mechanical properties.Though, deeper investigation of factors influencing conductivity of tool steels is needed. This includes the conductivity of temper carbides as well as the influence of short-time heat treatment on the conductivity of tool steels. Regarding the copper infiltrated steels, the kinetic of formation and coarsening of iron precipitates in the copper and the increase of the strength are focused.

冷成形和热成形是工具钢的主要应用，例如在板材成形和锻造领域。通常，这些钢的开发和选择会考虑拉伸和压缩强度或耐磨性和耐腐蚀性等技术方面，而热导率和导电性等物理性能很少被注意到。在之前的资助期间，分析了化学成分和热处理条件对所选工具钢导电性的影响。结果表明，热处理产生的固溶状态对工具钢的导热系数有很大影响，尤其是通过碳化物的形成和溶解。下一步，研究了碳化物的形成与电导率的关系。相应地，碳化物的形成和粗化，特别是富铬碳化物的形成和粗化，导致电导率显著增加，降低了电导率降低合金元素在基质中的含量。此外，还研究了渗铜工具钢的导电基本原理。这些材料能够结合高导电性和良好的抗压强度。在渗透过程中，铜被铁净化，极大地降低了其导电性。良好的定向热处理能够在一定程度上逆转这一效应。在提交的研究项目中，所获得的结果将转移到挤压硬化的技术应用中。为了实现这一点，应进行工具内淬火的仪表化热成形实验。所使用的工具将具有通过热处理调整的导电性，从而使工具导电性与所生产的零件的机械性能相关联。特别是，工具的部分热处理和添加到工具中的功能渗层将被研究。由于刀具导热系数的局部调节，制造的零件可以获得分级的机械性能，但影响工具钢导热系数的因素还需要进一步研究。这包括回火碳化物的导电性以及短时热处理对工具钢导电性的影响。对于渗铜钢，重点研究了铜中铁析出物的形成和粗化动力学以及强度的提高。

项目成果

Thermo-physical properties of heat-treatable steels in the temperature range relevant for hot-stamping applications

• DOI: 10.1007/s10853-015-8829-z
• 发表时间: 2015-01
• 期刊: Journal of Materials Science
• 影响因子: 4.5
• 作者: Jakob Kuepferle;J. Wilzer;S. Weber;W. Theisen

Effect of heat treatment on phase structure and thermal conductivity of a copper-infiltrated steel

• DOI: 10.1007/s10853-015-8919-y
• 发表时间: 2015-05-01
• 期刊: JOURNAL OF MATERIALS SCIENCE
• 影响因子: 4.5
• 作者: Klein, S.;Weber, S.;Theisen, W.
• 通讯作者: Theisen, W.

The influence of heat treatment and resulting microstructures on the thermophysical properties of martensitic steels

• DOI: 10.1007/s10853-013-7665-2
• 发表时间: 2013-12-01
• 期刊: JOURNAL OF MATERIALS SCIENCE
• 影响因子: 4.5
• 作者: Wilzer, Jens;Luedtke, Fabian;Theisen, Werner
• 通讯作者: Theisen, Werner

Thermal conductivity of advanced TiC reinforced metal matrix composites for polymer processing applications

• DOI: 10.1177/0021998313516143
• 发表时间: 2015-01
• 期刊: Journal of Composite Materials
• 影响因子: 2.9
• 作者: J. Wilzer;M. Windmann;S. Weber;H. Hill;A. V. Bennekom;W. Theisen

Carbide Precipitation During Tempering of a Tool Steel Subjected to Deep Cryogenic Treatment

• DOI: 10.1007/s11661-014-2202-8
• 发表时间: 2014-05-01
• 期刊: METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
• 影响因子: 2.8
• 作者: Gavriljuk, V. G.;Sirosh, V. A.;Kortmann, A.
• 通讯作者: Kortmann, A.