The Train wheel is composed of two wheels fixed on the axle with an interference fit. They rotate with the axle and do not have any independent relative movement like other automobile wheels.
The steel for wheels and tyre is killed steel smelted by electric furnace or converter. According to the production process, it is divided into rolled steel wheels and cast steel wheels.
Generally speaking, higher-end wheels such as passenger cars and high-speed trains are usually produced by rolling steel.
For heavy-duty trains, the wheel-rail contact stress is large, especially under high stress, the area of the wheel-rail contact area is enlarged, the wheels wear large when the train is running, and contact fatigue failure is prone to occur. Therefore, the steel for heavy-duty train wheels requires higher wear resistance and fatigue resistance, and at the same time, thermal fatigue damage resistance must be considered.
Train Wheel Materials:
Steel made by electric or alkaline oxygen process
• Forged steel should be of sedated quality
• Maximum hydrogen content must not exceed 3 ppm
• The maximum nitrogen content must not exceed 0.007%
Train Wheel Steel:
The chemical composition of the steel for Cast Wheel |
|
C |
0.47% to 0.57% for type A used for carriage stock 0.57% to 0.67% for type B used for wagon stock |
Mn |
0.60 to 0.80% |
P |
0.03% max |
S |
0.03% max |
Cr |
0.15% max |
Ni |
0.25% max |
Mo |
0.06% max |
Combined % for Cr, Ni & Mo must be 0.40% max |
Mechanical Properties of Cast Wheels
Sl. No. |
Particulars |
Type A |
Type B |
1 |
Tensile Strength at 15 mm below tread face |
900 N/m2 min. |
930 N/m2 min. |
2 |
Tensile strength at middle of the web |
800 N/m2 min. |
800 N/m2 min. |
3 |
Minum yield strength at 15 mm below tread face |
50% of UTS |
50% of UTS |
4 |
Minimum yield strength at middle of the web |
50% of UTS |
50% of UTS |
5 |
Minimum elongation at 15 mm below tread face |
5.0% |
4.5% |
6 |
Minimum elongation at middle of the web |
7.0% |
7.0% |
7 |
Hardness range at 15 mm below tread face |
255-320 BHN |
271-341 BHN |
8 |
Minimum impact strength at 15 mm below tread face |
10 J/cm2 at 20 deg C |
-- |
Train Wheel Components:
The train wheels are divided into the following parts
1. Hub
2. Disc
3. Tyre
1.Hub
1) The hub is the central part of the wheel, and the wheel is fixed on the axle by the following method of interference fit.
2) The thickness of the wheel is in the hub part.
3) UT detailed information is marked on the Hub
2.Disc
1) The disc is the part of the wheel hub and the tyre between the wheels.
2) This part is the thinnest part of the wheel, because it does not touch the railway nor the shaft.
3. Tyre
1) The tyre is the part of the railway that is in contact with the tyre and is worn out during service.
2) The contour of the tyre is for the safe operation of the train.
Wheel Gauge
Description |
Std |
Max |
Min |
Coach MG |
930 |
932 |
929 |
ICF coach BG |
1600 |
1602 |
1599 |
LHB coach |
1600 |
1601 |
1599 |
Wagons |
1600 |
1602 |
1599 |
Wheel Diameter
Description |
Std |
Cond |
Coach MG |
|
|
ICF coach BG |
915 |
825 |
LHB coach |
915 |
845 |
BOXN |
1000 |
906 |
UIC |
1000 |
860 |
BLC |
840 |
780 |
Stamp details:
Whenever the axles are updated, the workshop should type the following detailed information magazine face on the 5mm letters
1) Press the location
2) Press the date
3) Suppress pressure
Whenever the UT is completed, the details shall be cold stamped on the inner hub fillet with a 6 mm punch, not more than 1.5 mm deep.
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