Deng Xiangxing, right, is at the steel plant in Hebei. (Photo/Deng Xiangxing)
Chongqing - Compared to fuel-powered vehicles, new energy vehicles have a heavier curb weight, which increases the demand for lightweight materials.
Deng Xiangxing, a PhD in materials science, recalled that when he was in his student period, people around him regarded steel as an old and traditional industry with low profits, and his classmates were not keen on working in the steel sector after graduation. However, with the rise of the new energy vehicle industry, many new materials have emerged in the steel industry, making it a hot and sought-after field.
Currently, Deng leads a team at MatFavor working on the development of advanced high-strength steel designed specifically to meet the lightweight demands of new energy vehicles. The material entered mass production at a steel plant in 2024 and is now in the final phase of stability testing. Several automotive companies are already lining up to collaborate, and it is expected to be widely used in vehicles starting in 2025.
NEV boom sparks lightweight demand
In November 2024, China’s annual production of new energy vehicles surpassed 10 million units for the first time, marking a new phase of high-quality development for the NEV industry.
This has been accompanied by significant changes throughout the industry's supply chain.
Although new energy vehicles do not have engines or gearboxes like fuel-powered vehicles, they are equipped with three-electric systems, adding an extra 200 to 300 kilograms to the vehicle's weight.
Moreover, as the demand for longer driving ranges increases, more batteries are required, further increasing the weight. As NEVs compete to enhance their range, the demand for lightweight materials has surged.
From a technical standpoint, automotive companies are exploring three main directions for replacing the current mainstream material, low-carbon steel: carbon fiber composites, aluminum-magnesium alloys, and advanced high-strength steel. However, the first two options are still in the early stages of technological exploration and development, with high raw material costs and low processing efficiency.
To address this, both academia and industry have turned their focus to advanced high-strength steel. One such company is MatFavor, a startup incubated by the Chongqing Innovation Center of Beijing Institute of Technology.
Deng, a "post-90s," has shifted his study focus from mechanical engineering to materials science.
"When I started my master's degree in materials science at South China University of Technology, Tesla began mass production, and new materials like lithium batteries and graphene were gradually entering the market. Many of my classmates went into related industries, but I chose to focus on hard alloys during my PhD."
After completing his postdoctoral research at the Chongqing Innovation Center in September 2022, Deng joined MatFavor and began working with Zhao Yan, the director of the Lightweight Technology Research Institute of Chongqing Innovation Center, to develop a new type of uncoated, shot-blast-free hot-formed steel.
Deng Xiangxing is working at the lab of the Chongqing Innovation Center of Beijing Institute of Technology. (Photo/Deng Xiangxing)
Addressing industry challenges
According to Deng, parts of new energy vehicles, such as the A-pillars, B-pillars, crash beams, door rings, and front and rear floor H-frames, require both lightweight materials and high safety standards. Two commonly used materials in the industry for these components are bare plates and Al-Si-coated plates.
Bare plates are cheaper but prone to oxidation, requiring shot blasting to remove the oxide scale. However, the shot blasting process presents two problems: pollution and the potential to affect part precision. As a result, many environmental authorities do not permit the construction of new bare plate production lines.
To address this, the international steel giant ArcelorMittal developed an Al-Si coated material, where aluminum and silicon coatings are applied to the surface of the bare plate to prevent oxidation and eliminate the shot blasting process. However, this material is significantly more expensive than domestic alternatives, and vehicles made with it face patent restrictions when exported to Europe and the U.S.
"So good things aren't cheap, and cheap things aren't good," Deng said. The hot-formed steel LumiSword, developed by his team, has a tensile strength ranging from 1,500 MPa to 2,000 MPa and achieves weight reduction by replacing thickness with strength. For instance, he explained that using hot-formed steel in the A and B pillars of a vehicle can reduce weight by 20-30 percent.
Compared to bare plates and Al-Si coated plates, LumiSword hot-formed steel offers significant advantages in vehicle lightweighting. It not only eliminates the need for coating, plating, and shot blasting processes but also allows for direct painting. LumiSword meets the requirements for weight reduction, strength, and safety, and it holds independent intellectual property rights with no patent restrictions, making it an ideal material for the lightweighting of new energy vehicles.
Hot-formed steel demand surpasses 2 million tons
As the project leader for the LumiSword hot-formed steel, Deng has led his team over the past four years to determine the material composition and ratio, followed by establishing the production process. They conducted hundreds of tests.
Once the composition and parameters were finalized, the team had to carry out pilot production tests. In the winter of 2023, Dr. Zhao Yan led a team to a steel plant in Hebei Province for material trials.
"It was extremely cold in Hebei, and it even snowed before the Spring Festival," Deng recalled. To avoid affecting normal production, the trials were conducted at night. Often, at two or three in the morning, while snow was falling outside, the MatFavor team and the steel plant team, about a dozen people, would sit in a small office outside the production line, sipping spicy soup, while passionately discussing the process.
From melting, casting, and hot rolling to annealing, the team spent a year in the lab and at the factory, working half the time in each until they finally perfected the entire process. Then, Deng began visiting automotive parts factories.
By the end of 2024, Deng had taken the product to three stamping plants in Chongqing, Zhejiang, and Hunan, respectively. At first, the results were not ideal, but the performance gradually improved through continuous improvements in formulas and processes and repeated testing, achieving the best results for the stamped parts.
Finally, LumiSword hot-formed steel entered mass production at the beginning of 2024, and several major automakers expressed interest in collaborating. Large-scale adoption is expected in 2025.
"A white body of a vehicle, completed but not yet painted, excluding parts like doors and the engine hood, weighs about 350 kilograms, and approximately 20 percent of that is made of hot-formed steel. With around 30 million vehicles sold annually in China, the hot-formed steel market should exceed 2 million tons," Deng said.
He also noted that the demand for hot-formed steel is skyrocketing the rapid growth of China’s automotive industry, especially in new energy vehicles. is skyrocketing Many of his junior schoolmates,avoided research in the steel sector, are now seeking information on the future applications of hot-formed steel. The its future applicationsaditional steel industry.
(Zhuang Chunmeng, as an intern, also contributed to this report.)
(She Zhenfang and Hou Yue, reporters from Chongqing Daily, contributed the Chinese version of this report.)