Revolutionizing car body manufacturing using a unified steel metallurgy concept

Reuse, remanufacturing and recycling in the steel sector

The global steel sector is undergoing a transition from being a major CO2 emitter to a more sustainable circular material service provider, moving towards (near) net zero CO2 through combined strategies of reuse, remanufacturing, recycling and changes to primary steelmaking. This paper considers the transition using the UK as an example, based on the current sector state and future plans/opportunities. Some key enablers/barriers have been identified, and case studies are presented on the current state of knowledge and technology developments. For example, increasing reuse/remanufacturing requires data on the component's remaining life at the end-of-product life; in this work use of in-service monitoring for steel-intensive applications in the transport sector is discussed identifying sensor types/locations for fatigue loading assessment for different use conditions to feed into material/product passports for reuse/remanufacturing decisions. Increased recycling of obsolete scrap has implications for composition control with increases in residual elements, such as Cu, Sn, Cr and Ni inevitable. Current and future approaches to recycling and scrap sorting are discussed along with case studies for how residual elements affect microstructural development during steel processing, including effects on recrystallization, phase transformation and fine-scale precipitation, which potentially could be exploited to give increases in product strength. This article is part of the discussion meeting issue 'Sustainable metals: science and systems'.

Multi-Scale Microstructural Tailoring and Associated Properties of Press-Hardened Steels: A Review

High-strength press-hardened steels (PHS) are highly desired in the automotive industry to meet the requirement of carbon neutrality. This review aims to provide a systematic study of the relationship between multi-scale microstructural tailoring and the mechanical behavior and other service performance of PHS. It begins with a brief introduction to the background of PHS, followed by an in-depth description of the strategies used to enhance their properties. These strategies are categorized into traditional Mn-B steels and novel PHS. For traditional Mn-B steels, extensive research has verified that the addition of microalloying elements can refine the microstructure of PHS, resulting in improved mechanical properties, hydrogen embrittlement resistance, and other service performance. In the case of novel PHS, recent progress has principally demonstrated that the novel composition of steels coupling with innovative thermomechanical processing can obtain multi-phase structure and superior mechanical properties compared with traditional Mn-B steels, and their effect on oxidation resistance is highlighted. Finally, the review offers an outlook on the future development of PHS from the perspective of academic research and industrial applications.

Alloy Profusion, Spice Metals, and Resource Loss by Design

One of the most unfortunate attributes of technology’s routine and widespread use of most of the elements in the periodic table is the abysmal functional recycling rates that result from the complexity of modern technology and the rudimentary technological state of the recycling industry. In this work, we demonstrate that the vast profusion of alloys, and the complexities and miniaturization of modern electronics, render functional recycling almost impossible. This situation is particularly true of “spice metals”: metals employed at very low concentrations to realize modest performance improvements in advanced alloys or complex electronics such as smartphones or laptops. Here, we present a formal definition of spice metals and explore the significant challenges that product design decisions impose on the recycling industry. We thereby identify nine spice metals: scandium (Sc), vanadium (V), gallium (Ga), arsenic (As), niobium (Nb), antimony (Sb), tellurium (Te), erbium (Er), and hafnium (Hf). These metals are considered fundamental for the properties they provide, yet they are rarely recycled. Their routine use poses severe problems for the implementation of closed material loops and the circular economy. Based on the data and discussions in this paper, we recommend that spice metals be employed only where their use will result in a highly significant improvement, and that product designers place a strong emphasis on enabling the functional recycling of these metals after their first use.