Demand for rail transit castings across various segments is expected to be uneven in 2018, with some areas experiencing strong growth while others remain tepid.

　　As global economic development and industrial recovery gain momentum, the rail transit industry is entering a new round of growth in its cyclical upswing. In today’s context, marked by escalating energy crises and mounting environmental pressures, green rail transportation is set to become the dominant mode of global mobility. As a result, the rail transit sector is poised to embark on a fresh chapter of rapid, transformative growth on the world stage.

　　Rail transit components encompass a wide variety of castings, accounting for approximately 5% of China's total casting output. These products primarily include mechanical transmission gearboxes, high-power diesel engines, bolster and side frames for bogies, frame structures, vibration-damping devices, couplers with buffer systems, traction motors, disc-type braking systems, brake calipers, axle boxes, and other critical load-bearing parts—components essential for locomotives, freight cars, EMU trains, and urban rail equipment. Given their high technical specifications and significant manufacturing challenges, these castings are mostly small to medium-sized. Moreover, the materials and casting methods used are highly diverse. Importantly, the safety and reliability of these castings directly impact public transportation safety. Thus, it is clear that castings play an indispensable role in the rail transit industry.

　　According to statistical analysis from the Rail Transit Casting Branch of the China Foundry Association, the market demand for rail transit castings across various segments is expected to remain uneven in 2018. Currently, the domestic passenger transport sector increasingly relies on high-speed trains and EMUs to meet travel needs, while the demand for freight cars and locomotives continues to be driven by macroeconomic conditions and cargo volumes. Meanwhile, as subway networks expand in terms of operational mileage, the demand for subway vehicles is set to surge dramatically year by year. A detailed analysis follows:

　　High-speed train sector: Market demand shows an upward turning point

　　In 2016, the number of high-speed trainsets put out for tender was only 110 standard units. From January to November 2017, China Railway Corporation awarded contracts for a total of 205 standard trainsets, representing an impressive year-on-year increase of 86.4%. This growth was largely driven by the boost from the "Belt and Road" initiative, which has continued to fuel a steady rise in overseas orders. As a result, companies primarily focused on producing castings for high-speed train components were particularly busy in 2017—for instance, CRRC Qishuyan Locomotive & Rolling Stock Technology Research Institute Co., Ltd. saw its aluminum alloy gearboxes for high-speed trainsets reach an all-time peak, while Zhuzhou Jiufang Foundry Co., Ltd., specializing in castings for traction motors, worked tirelessly to meet the growing demand and fulfill its order backlog.

　　Looking at the future development outlook, the newly opened high-speed rail mileage is rebounding from its recent low, coupled with increased operational density, signaling an upward turning point in demand for high-speed trains. In 2016, the state released the "Medium- and Long-Term Railway Network Plan," aiming to achieve over 30,000 kilometers of high-speed railway by 2020, with China's operational high-speed rail mileage expected to exceed 38,000 kilometers by 2025. From a construction progress perspective, China’s new high-speed rail mileage is set to grow rapidly over the next three years compared to 2017—marking the lowest point—before accelerating significantly starting in 2018, thereby driving a recovery in demand for rail transit equipment. As a result, orders for cast components such as transmission gearboxes, couplers and buffers, brake discs, calipers, axle box bodies, positioning arms, and traction motors are poised to rebound swiftly during this period.

　　Additionally, investment in intercity railways has accelerated, becoming one of the key drivers behind the growing demand for high-speed trains. According to the "Comprehensive Transportation Network Plan for Urbanized Areas," jointly released in December 2015 by the National Development and Reform Commission and the Ministry of Transport, China is set to build approximately 8,000 kilometers of new intercity railways by 2020, connecting 98% of major hub cities and nearly 60% of counties (and county-level cities). If we calculate based on an operational density of 0.9 high-speed train cars per kilometer, the newly added 8,000 kilometers of intercity railways will generate a demand for 7,200 high-speed train cars—equivalent to 900 standard trainsets—resulting in an average annual demand of 180 standard trainsets. Notably, research and development of freight-oriented high-speed train sets has already been initiated, and this initiative is expected to become a significant contributor to future growth in high-speed train demand.

　　Urban rail and metro sector: Expected to grow by more than 20%

　　As the operational mileage of subways continues to grow year after year, so does the demand for subway vehicles—expected to maintain over 20% growth in 2017. Tram-based metros, light rails, monorails, intercity rapid transit systems, maglev trains, and modern trams are all thriving, leading to a significant surge in order demand from casting markets for components such as gearboxes, brake discs, and traction motors.

　　Truck Sector: Officially Signals Market Recovery and Revival

　　In 2016, a total of 25,272 freight cars were tendered, officially signaling the recovery and rebound of the freight car market. On January 19, 2017, China Railway Corporation launched its largest-ever freight car tender since its establishment, with an impressive 40,000 vehicles—representing a 58% increase compared to the entire year of 2016. This procurement round included 20,000 NX70A-type general-purpose flatcars and another 20,000 X70-type container-specialized flatcars. Meanwhile, the Rail Transit Casting Branch, primarily composed of freight car component manufacturers, has seen a surge of vitality as these large-scale freight car orders bring new opportunities to its numerous member companies.

　　Locomotive Sector: Noticeable Increase in Bidding and Delivery Volumes

　　In 2016, constrained by the slowdown in the locomotive bidding process, only slightly more than 100 locomotives were delivered throughout the year. However, as freight car bidding and delivery volumes picked up in 2017, demand for locomotives also saw a significant increase. According to statistics, on January 26, 2017, China Railway Corporation issued a tender announcement, calling for bids on 586 passenger and freight electric locomotives at once—495 of which were freight models and 91 designed for passenger service. On November 3, 2017, China Railway Corporation launched another tender for 160 km/h (6-axle, 7,200 kW) AC-driven passenger electric locomotives. Then, on December 11, 2017, CRRC Qishuyan Co., Ltd. signed a procurement contract with China Railway Corporation for 30 units of 4,400-horsepower AC-driven shunting diesel locomotives, model HXN5B. As a result, locomotive and low-speed passenger car component casting enterprises—whose core businesses include locomotive mechanical transmission gearboxes, traction motor castings, brake discs, and other key parts—finally found some relief amid the renewed demand.

　　Looking at the current situation, the rail transit equipment industry is expected to maintain growth of 15% to 20% over the next 3 to 5 years. The annual increase in high-speed trainsets is projected to remain steady at 300 to 400 units, with an annual market size ranging from 60 billion to 80 billion yuan. Meanwhile, high-speed trainsets will require approximately 2,560 tons of castings each year.

　　Railway trains are expected to see an average demand of 70,000 to 80,000 units. Based on an average usage of 6 tons of supporting castings per freight car, this translates to an annual requirement of 480,000 tons of castings. Meanwhile, locomotives are projected to have an annual demand of 700 to 1,000 units. Calculated at an average of 10 tons of supporting castings per railway locomotive, the locomotive industry will require approximately 10,000 tons of castings each year.

　　The number of railway passenger cars (carriages) is expected to maintain a 4% growth, with annual demand projected at around 7,000 units. Based on an average usage of 1.5 tons of supporting castings per railway passenger car, the industry will require 10,500 tons of castings each year.

　　Over the next five years, urban rail transit is set to experience explosive growth, with expectations of sustained annual increases of 2,500 to 3,000 vehicles for an extended period ahead. Based on an average usage of 1.5 tons of supporting castings per urban rail vehicle, the annual demand for castings in this sector is projected to reach 4,500 tons.

　　2018: Focus on overcoming the following technical challenges

　　In terms of technological innovation, rail transit casting enterprises will focus on the following key tasks in 2018:

　　First, CRRC has established a casting expert group to collaboratively tackle the challenges in the development and production of cast components for rail transit systems. In the area of casting simulation and modeling technology, we plan to organize joint workshops aimed at achieving more comprehensive and reliable defect predictions. Specifically, our focus will expand beyond the traditional analysis of shrinkage defects to include the assessment of external flaws such as slag inclusion, cracks, and cold shuts—and even extend to predicting the resulting microstructure and mechanical properties, ultimately enabling us to evaluate the performance characteristics of the final products. Additionally, regarding waste sand management for steel castings, we intend to jointly conduct more in-depth technical research to address critical issues like the recycling of spent water-glass sand used in wet-process regeneration, as well as the residual sodium (Na) concerns associated with dry-process regeneration. We’ll also explore ways to improve the overall utilization rate of old core sand in rail transit steel castings and optimize the sand-to-metal ratio for various thin-walled castings in this industry. Finally, we’ll discuss opportunities to broaden the application of advanced casting technologies—such as coated-sand casting and lost-foam casting—in the production of steel castings for rail transit systems.

　　Second, the integration of 3D printing technology with traditional casting techniques. 3D printing enables a rapid transition from design to finished product, minimizing intermediate steps, accelerating the product development cycle, and reducing costs—making it particularly well-suited for the quick prototyping of single new products or the production of small-batch, complex-structured castings in the rail transit industry. Key areas of focus include: first, directly sintering coated sand or ceramic powder to create sand molds or cores for gravity or low-pressure casting; and second, sintering high-performance polymer plastics or wax materials to rapidly fabricate metal parts using investment casting methods.

　　Third, the development and application of new steel and cast iron materials. In the area of innovative steel casting materials and processes, addressing the recurring issue of cracking in freight car coupler bodies and coupler tongues—particularly their inherent vulnerability—we must prioritize the development of high-strength, tough cast steel materials along with advanced manufacturing process research. Additionally, given the relatively poor wear resistance of critical wear-resistant components such as scraper blades and tamping rakes used in construction machinery, it is urgently necessary to tackle technical challenges related to new high-wear-resistant, high-toughness cast steel materials, aiming to create cutting-edge solutions that significantly enhance the wear resistance and service life of these products. Furthermore, considering the current demand for cast steel brake discs and other key cast steel components in high-speed trainsets—where stringent requirements exist regarding inclusions and gas content within the casting body—we will conduct research into medium-frequency furnace molten steel purification techniques and high-purity steel material preparation processes. This effort seeks to reduce gas and inclusion levels in the molten steel, thereby improving steel quality and ensuring superior intrinsic quality and performance of the final products. In terms of developing new cast iron materials and processes, we will embark on creating innovative cast iron materials and manufacturing technologies. Specifically, we aim to advance the development of next-generation, high-performance ductile iron materials, expanding their existing range of applications. Moreover, we will pioneer new low-temperature-resistant, high-performance ductile iron materials and associated manufacturing processes, enhancing the operational performance of ductile iron components under cold conditions and broadening their application horizons. Finally, by thoroughly investigating the mechanical and functional properties of various alloyed cast irons, we not only extend the versatility of cast iron materials but also lay a solid foundation for replacing numerous traditional cast steel components in rail transportation systems.

　　Fourth, research on casting processes for higher-strength aluminum alloy components and high-strength magnesium alloy materials. As rail transit equipment evolves toward higher speeds, greater energy efficiency, enhanced safety, and improved passenger comfort, the performance and quality requirements for cast aluminum alloy products have become increasingly stringent. At the same time, there is a growing demand for alloys that combine lightweight properties with superior strength and ductility. However, due to the relatively poor casting processability of these high-strength, tough Al-Cu series alloys and magnesium alloys, their application in the rail transit sector remains largely unexplored. Therefore, in 2018, breakthroughs are urgently needed in both improving the casting performance of Al-Cu series alloy and magnesium alloy materials, as well as developing innovative casting technologies tailored to these advanced materials.

　　Fifth, the research and development of aluminum-based composite braking materials. Aluminum-based composites boast high specific strength, specific stiffness, excellent high-temperature mechanical properties, along with a low thermal expansion coefficient and outstanding wear resistance. These attributes make them highly promising for applications across various industries, including rail transportation, aviation, aerospace, and automotive sectors. As a result, they have become a focal point in current metal-matrix composite research—and also represent a new direction for the advancement of cast aluminum alloys. Brake discs made from aluminum alloy composites used in rail transportation can achieve weight reductions of 50% to 60%, significantly lowering inertial forces, enhancing braking acceleration, improving heat dissipation efficiency, and minimizing wear. This, in turn, leads to enhanced overall brake disc performance. Currently, CRRC Qishuyan Institute is collaborating with Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) to jointly develop aluminum-based composite brake discs tailored for rail transportation applications.

　　Sixth, in the face of increasingly stringent pollution-control measures from the National Environmental Protection Department, coupled with rising environmental awareness and higher quality standards among major OEM customers, as well as escalating raw material costs, rail transit casting enterprises must continue to deepen lean management practices in 2018, focusing wholeheartedly on improving quality and boosting efficiency. This includes consistently promoting green casting and intelligent manufacturing, driving the transformation and upgrading of equipment and facilities at key process stations such as melting, pouring, grinding, and surface treatment. Additionally, companies should implement refined process control and on-site lean management, establish a robust system for preventing casting defect risks, optimize and balance quality costs, and ultimately build strong brand value for rail transit castings.