Manufacturing of powder metallurgical B-alloyed tool steels on an industrial scale

本课题来源于国家科研项目“B合金工具钢”(项目号232707733)。在该项目中，全面了解了工具钢中元素硼在凝固和固态组织形成过程中的作用和相互作用，以及形成的硼化物和碳化物的微观性能。在了解Fe-C-B系合金元素的作用和相互作用的基础上，以较低的合金成本获得了摩擦学和力学性能超过常规冷作工具钢的实验室合金。Deutsche Edelstahlwerke GmbH在“模具2019”大会上展示了这些发现，意识到了这一发展，并对B合金粉末冶金工具钢的大规模工业生产表现出极大的兴趣。在实验室对B合金冷作工具钢的组织形成过程有了基本的了解后，必须回答有关粉末雾化、粉末加工及其相关性能的几个新的科学技术问题。在前人研究项目“B合金钢”的基础上，本文提出的转移项目旨在开发气体雾化生产的B合金化工具钢种，并可采用粉末床熔化激光/金属(PBF-LB/M)和热等静压(HIP)技术进行深加工。为此，应以两种基本合金为例说明含B合金的冷作用钢的潜力。这些发展有助于获得经济前的知识。正在追求以下两个发展优先事项：1.开发可使用PBF-LB/M加工的B合金化工具钢，而无需预热底板等额外措施。2.热等静压二次硬化B合金粉末冶金工具钢的研制。

This transfer project is based on the research project "B-alloyed tool steels" (project number 232707733). In the project, a comprehensive understanding of the effect and interactions of the element boron in tool steels regarding the microstructure formation processes during solidification and in the solid-state, as well as the micro-properties of the borides and carboborides formed, was gathered. With the knowledge of the effect and the respective interactions of the alloying elements in the Fe-C-B system, laboratory alloys were derived whose tribological and mechanical properties exceed those of conventional cold work tool steels at the same time as lower alloy costs. By presenting these findings at the “Tooling 2019” conference, Deutsche Edelstahlwerke GmbH became aware of this development and signaled a great deal of interest in the large-scale industrial production of B-alloyed PM tool steels. After a fundamental understanding of the microstructure formation processes of B-alloyed cold work tool steels has been developed on a laboratory scale, several new scientific and technological questions regarding powder atomization, powder processing, and the associated properties must be answered. Based on the state of knowledge of the previous research project, "B-alloyed steels", the transfer project applied here aims to develop B-alloyed tool steel grades that are manufactured by gas atomization and can be further processed with the technologies Powder-Bed-Fusion Laser-Beam/Metal (PBF-LB/M) and hot isostatic pressing (HIP). For this purpose, the potential of B-alloyed cold work steels should be shown using the example of two basic alloys. The developments serve to gain pre-economic knowledge. The following two development priorities are being pursued: 1. Development of B-alloyed tool steel that can be processed using PBF-LB/M without additional measures such as preheating of the base plate. 2. Development of a secondary hardening B-alloy PM tool steel as a HIP product.