Axle Steering Knuckles as “power joint” of the Bogie System

Introduction of Axle Steering Knuckles

In the field of modern rail transit equipment manufacturing, bogies, as the core components that support train operation, have always been at the forefront of technological breakthroughs in the industry in terms of material engineering innovation. Among them, the axle steering knuckles, as the “power joint” of the bogie system, undertakes multiple missions such as transmitting driving force, adjusting the steering Angle, and buffering dynamic loads.

Material Selection And Development of Axle Steering Knuckles

Materials research and development to follow focuses on learning performance, environmental adaptation, and technology features of 3 the coordinate system. The current mainstream of 42 crmo4 alloy structural steel is the choice under the system of typical products:

Mechanics index level: the tensile strength of 900-1100 mpa, yield strength of no less than 650 mph, to ensure the maximum axle load of 30 tons of extreme conditions maintain structural integrity. Through computer-aided stress simulation, the fatigue life of this material under alternating loads reaches the level of 10^7 cycles.

Dimension of environmental considerations: after nitriding surface treatment, material surface hardness can reach HV700, cooperating with 0.3 mm depth of hardening layer;

In environmental dust, wear-resisting coefficient is 40% more than conventional materials. The specially proportioned Cr-Mo-V alloy system enables the components to maintain stable mechanical properties within the environmental window ranging from -40℃ to 120℃.

Technology Features of Axle Steering knuckles

Using the die forging forming process, the material under the 1150 ℃ heating temperature shows excellent liquidity and, with subsequent conditioning treatment, can achieve the overall hardness HRC28-32 with core toughness perfect balance. This gradient hardness distribution enables the component to simultaneously meet the requirements of surface wear resistance and overall impact resistance.

Function of Axle Steering Knuckles

In the practical operation of rail transit equipment, steering knuckle materials by micro structure control realize the three functions:

（1）Dynamic stress dissipation mechanism based on the theory of dislocation multiplication design of fine-grain strengthening structure, making the material under the wheel/rail impact, through the grain boundary sliding effectively disperse stress concentration. Experimental data show that the impact absorption energy of fine-grained steel treated by the controlled rolling and controlled cooling process reaches over 80J, which is 25% higher than that of the traditional process.

(2)Interface tribology optimization: the laser cladding technique was used to construct the gradient composite layer on the surface of the matrix-formed Cr3C2 cermet phase. This structure stabilizes the friction coefficient of the mating surface of the steering knuckle pin shaft within the range of 0.08-0.12. Combined with the solid lubricating film technology, the maintenance cycle is extended to 800,000 kilometers.

(3)Environmental response intelligent protection: innovation research and development of nanometer composite coating system, it contains pH response type corrosion inhibitor microcapsules. When the environmental humidity exceeds the threshold, the capsule automatically releases repair factors to form a self-repairing passivation film on the metal surface. Salt spray tests show that this technology extends the corrosion resistance life of components by more than three times.

Parameter of Axle Steering Knuckles

Package of Axle Steering Knuckles

Polybag+Carton box+Wooden case/Pallet, according to customer’s request

Company Profile

Luoyang Fenyo Heavy Industries Co., Ltd. was founded in 1998, covers an area of 72,600㎡, with more than 300 employees, 32 technicians, including 5 senior engineers, 11 assistant engineers, and 16 technicians. It has been rated as Luoyang Engineering Technology Center, Luoyang Technology R&D Center, and National High-tech Enterprise for many times.
Our production capacity is 30,000 tons per year. Currently, we mainly produce cast steel, cast iron (gray iron, ductile iron, etc.), processing of finished product and component assembly.the products have been exported to Russia, the United States, Germany, Argentina, Japan, France, South Africa,Italy and other countries.

FAQS

Q1: Are you a manufacturer or trading company?
A:Yes,our company was founded in 1998, with nearly 30 years in casting industry, a total area of 72,600㎡, with a factory building area of 51,000㎡.
Q2. What are your main products?
A: We primarily focus on steel casting, iron casting, finished product machining, and component assembly production.
Q3: How precision can you produce casting parts?
A: We have the capability of producing casting parts with different casting processes. The production is strictly comply with ISO 9001, ISO 14001 and ISO45001,EN15085, IRIS.
Q4. Can you produce according to the samples?
 Yes, we can produce by your samples or technical drawings. We can build drawings for you after we get your samples too.
Q5: How do you do Quality Control before delivery?
A: Quality inspection is a very important factor to guarantee the quality of steel casting parts. We follow 3 times of inspection during the whole production process. And we will provide material testing report, dimensional testing report, and mechanical properties testing report to our clients before delivery.

It you are interested in any products,please feel free to contact us.
Contact:Cathy Xu
Email:sales@railwaypart.com
Mobile:008615515321683