High-Speed Rail Forgings: Meeting the 400 km/h Challenge
Release time：
2026-09-23
High-Speed Rail Forgings: Meeting the 400 km/h Challenge
Nanjing Liju Precision Forging Co., Ltd. ｜ Industry News ｜ September 2026
Cover: forged axle blanks, gear blanks and bogie fittings for high-speed rolling stock (illustration — replace with factory photography)
The fastest commercial trains in the world are about to get faster. China's CR450 high-speed train — designed for a commercial operating speed of 400 km/h — has passed all type tests and completed 300,000 km of service trials, according to the China Academy of Railway Sciences. Full operational assessment and design finalization are scheduled for 2026, with comprehensive testing on the Chengdu–Chongqing Middle Line ahead of entry into service.
Every step up in speed sends a harder question through the supply chain, and no component feels it more directly than the forged parts that carry the train: axles, gear blanks, bogie fittings, brake components and structural brackets. This article explains what 400 km/h actually demands of a forging — and what that means for OEM buyers qualifying suppliers for next-generation programs.
The 400 km/h Era Is Almost Here
During test runs in October 2025 on the Shanghai–Chongqing–Chengdu high-speed line, a CR450 train reached a single-train test speed of 453 km/h and a relative passing speed of 896 km/h between two trains. The design certification ceiling is 450 km/h; commercial operation is planned at 400 km/h — about 14% faster than today's 350 km/h services.
The consequences cascade. Braking performance is one example: CR450 must stop from 400 km/h within 6,500 meters on a dry, straight track — the same distance today's CR400 needs from 350 km/h, according to China State Railway Group. Aerodynamic drag was cut by about 22% through redesigned noses and bodywork. Weight becomes a premium again: every kilogram saved on a bogie reduces track load, energy consumption and lifecycle cost.
For forgings, the message is direct. Higher speed raises wheel–rail forces, dynamic loads and fatigue cycles; lighter designs demand stronger, tougher materials with tighter dimensional control. The next generation of high-speed rolling stock is, in effect, a tougher specification sheet for every forged part beneath the floor.
What 400 km/h Does to a Forged Part
Axles are the load-bearing heart. High-speed axles are forged (or rolled) from vacuum-degassed alloy steel and defined by EN 13261, the European product standard. The workhorse grade is EA4T, a nickel-chromium-molybdenum steel requiring minimum 700 MPa tensile strength and 550 MPa yield after quenching and tempering. The latest revision, EN 13261:2024, tightens product requirements further.
Hollow axles are becoming the norm for high speed. Boring a concentric hole through a forged solid axle cuts unsprung mass — critical for ride quality and track forces at 400 km/h — and allows sensors to be routed through the axle bore for condition monitoring. The discipline is demanding: bore concentricity with the journal surfaces is essential, because eccentricity causes vibration that shortens bearing life.
Fatigue life is engineered, not assumed. EN 13261 requires vacuum-degassed steel with strict limits on non-metallic inclusions and internal defects, and 100% ultrasonic testing of safety-critical axles. Research on EA4T now extends to very-high-cycle fatigue beyond 10⁸ cycles, reflecting the reality that a 400 km/h axle accumulates load cycles far faster than its predecessors. Controlled grain flow from closed-die or open-die forging, uniform heat treatment and clean machined surfaces are what convert a good material into a dependable part.
Beyond the axle. Gear blanks, brake disc hubs, bogie frame fittings, couplers and brackets face the same logic: near-net-shape forging to preserve grain flow and minimize material waste, followed by precision machining on functional surfaces. Higher-strength grades are being qualified alongside EA4T to support the weight targets of next-generation platforms.
The Manufacturing Disciplines Behind a 400 km/h Axle
Suppliers to next-generation programs are audited on disciplines, not adjectives:
Material control — vacuum-degassed steel, certified heat numbers, and a traceability chain from melt to finished part.
Forging capability — the press capacity, die engineering and process repeatability to produce large, consistent blanks; automation matters when every batch must be identical.
Machining depth — concentric boring, journal finishing and tight tolerances on functional surfaces, ideally under one roof to shorten lead times and control variation.
Complete inspection — ultrasonic testing, spectro analysis, metallographic examination, tensile testing and CMM dimensional verification, documented per part.
Quality system — ISO 9001 as the baseline, IATF 16949 where components also serve automotive, and a credible path toward railway-specific schemes such as ISO 22163 (IRIS).
Where a Precision Forging Partner Fits in Next-Generation Programs
Global programs — in China, Europe, India and emerging high-speed markets — all run on the same logic: platform development, then disciplined qualification of suppliers who can hold a standard across large series. A capable forging partner shortens that qualification by combining engineering review, first-article samples and documentation with production.
Nanjing Liju Precision Forging has produced precision forgings since 1998. From its 34,000 m² plant in Nanjing's Liuhe Economic Development Zone, the company serves customers on three continents with ISO 9001, IATF 16949 and ISO 14001 certification, exporting to the United States, Germany, Italy, Canada and Japan since 2003.
Fig. 1: Precision machining of a long axle forging on a CNC turning line (illustration — replace with factory photography)
Its forging department runs 300T–1,600T friction screw presses, automated closed-die hot forging lines with robotic handling, a cold forging shop, machining and in-house CAD/CAM die design. Its product portfolio covers railway accessories and structural fittings, automotive components, high-speed-rail parts, aviation fittings (including components for Airbus programs), mining and hydraulic parts, forklift components for Toyota and Crown, copper connectors and aluminum forgings.
Every part is released through an in-house inspection laboratory — hardness testing, profile projection, CMM, tensile testing, metallographic analysis, spectro analysis and surface roughness measurement — the same toolkit rail buyers audit before qualifying a supplier.
How to Start a Qualification Conversation
To evaluate a component against a next-generation program, Liju's engineers need three inputs: drawings or 3D models, the target material and standard reference (for example EN 13261 with the required steel grade), and annual volumes with delivery terms. In return, the customer receives a design-for-manufacturing review, first-article samples, PPAP-style documentation, full traceability records and one accountable partner from quotation to series production.
Send your drawings today to sales@njliju.com for a DFM review and quotation. Or call +86 138 5144 1727. The plant: No. 6 Longhua Road, Liuhe Economic Development Zone, Nanjing, China.
Speed is a test. Every extra kilometer per hour asks the supply chain a harder question — and the forged parts beneath the floor answer it first. Choose a partner who treats every forging as load-bearing.
Sources ｜ 资料来源（核验日期 2026-09-23）：
中国国家铁路集团 / 人民日报 ｜ CR450 动车组运用考核与制动指标
新华网 / 中国日报 ｜ CR450 试验时速 453 公里、交会 896 公里
中国网铁路频道 / 国际科技创新中心 ｜ CR450 2026 年完成全部运用考核与设计定型
iTeh / BSI ｜ EN 13261:2024 车轴产品要求（EA1N/EA1T/EA4T）
交通运输工程学报 / Frontiers in Materials ｜ EA4T 空心车轴疲劳极限与超高周疲劳研究
ISO ｜ ISO 22163:2023 Railway quality management system
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