Table 1
Summary of the description of research samples.
| Sample no. | Manufacturer | Year of production | Steel grade | Height of the rail (mm) | Width of the rail foot (mm) |
|---|---|---|---|---|---|
| 1 | Dortmunder Union | 1875 | Low carbon steel | 101* | 93 |
| 2 | Phoenix West | 189? | Medium carbon steel | 130* | 116 |
| 3 | Aachener Hütte | 1879 | Low carbon steel | 117* | 109 |
| 4 | KRUPP | 1894 | Medium carbon steel | 127* | 100 |
| 5 | ArcelorMittal Poland S.A. | 2024 | R260 | 149 | 125 |
| 6 | ArcelorMittal Poland S.A. | 2024 | R350HT | 149 | 125 |
*Measurement after operation in the axis of symmetry of the rail.

Figure 1
Dortmunder Union rail.

Figure 2
Phoenix West rail.

Figure 3
Aachener Hütte rail.

Figure 4
KRUPP rail.

Figure 5
ArcelorMittal Poland S.A. rail in steel grade R260.

Figure 6
ArcelorMittal Poland S.A. rail in steel grade R350HT.
Table 2
Chemical composition of individual samples for the main elements.
| Sample no. | Mass % | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| C | Si | Mn | P | S | Cr | Al | V | N | |
| 1 | 0.173 | 0.53 | 0.589 | 0.105 | 0.06 | 0.008 | 0.002 | 0.013 | 0.0332 |
| 2 | 0.46 | 0.011 | 0.418 | 0.064 | 0.07 | 0.009 | 0.007 | 0.001 | 0.0051 |
| 3 | 0.20 | 0.034 | 0.222 | 0.096 | 0.045 | 0.007 | 0.002 | 0.006 | 0.0121 |
| 4 | 0.422 | 0.19 | 0.69 | 0.075 | 0.046 | 0.010 | 0.003 | 0.01 | 0.0112 |
| 5 | 0.71 | 0.31 | 1.04 | 0.0073 | 0.014 | 0.008 | 0.003 | 0.003 | 0.0070 |
| 6 | 0.79 | 0.38 | 1.12 | 0.011 | 0.013 | 0.07 | 0.004 | 0.002 | 0.0057 |
Table 3
Chemical composition of individual samples for residual elements.
| Sample no. | Mass % | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Cu | Ni | Sn | As | Nb | Ti | Mo | B | Cu + 10Sn | |
| 1 | 0.149 | 0.014 | <0.001 | 0.038 | 0.001 | 0.001 | <0.001 | 0.0005 | 0.159 |
| 2 | 0.135 | 0.027 | 0.002 | 0.038 | 0.001 | <0.001 | <0.001 | 0.0003 | 0.155 |
| 3 | 0.009 | 0.013 | <0.001 | 0.019 | 0.001 | <0.001 | <0.001 | 0.0004 | 0.019 |
| 4 | 0.08 | 0.01 | <0.001 | 0.023 | 0.001 | <0.010 | <0.010 | 0.0003 | 0.09 |
| 5 | 0.02 | 0.014 | 0.0006 | 0.001 | 0.001 | 0.0009 | 0.003 | 0.0004 | 0.026 |
| 6 | 0.03 | 0.016 | 0.002 | 0.001 | 0.001 | 0.0009 | 0.006 | 0.0005 | 0.05 |
Table 4
Range of chemical composition of the R260 and R350HT grades for the main elements.
| Steel grade | Mass % | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| C | Si | Mn | P max | S max | Cr | Al max | V max | N max | |
| R260* | 0.62–0.80 | 0.15–0.58 | 0.70–1.20 | 0.025 | 0.025 | ≤0.15 | 0.004 | 0.030 | 0.009 |
| R350HT* | 0.72–0.80 | 0.15–0.58 | 0.70–1.20 | 0.020 | 0.025 | ≤0.15 | 0.004 | 0.030 | 0.009 |
*The requirements are given for steel in the liquid state.
Table 5
Range of chemical composition of the R260 and R350HT grades for residual elements.
| Steel grade | Mass % | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Cu | Ni | Sn | As | Nb | Ti | Mo | B | Cu + 10Sn | |
| R260 | 0.15 | 0.10 | 0.030 | — | 0.01 | 0.025 | 0.02 | — | 0.35 |
| R350HT | 0.15 | 0.10 | 0.030 | — | 0.04 | 0.025 | 0.02 | — | 0.35 |

Figure 7
Images of the ferrite-pearlite microstructure of the Dortmunder Union rail. a) magn. 100x, b) magn. 500x.

Figure 8
Images of the ferrite-pearlite microstructure of the Phoenix West rail. Coarse-plate perlite is visible. a) magn. 100x, b) 500X.

Figure 9
Images of the ferrite-pearlite microstructure of the Aachener Hütte rail. a) magn. 100x, b) magn. 500x.

Figure 10
Images of the microstructure of the ferrite-pearlite Krupp rail. a) magn. 100x, b) magn. 500x.

Figure 11
Images of the microstructure of a fully pearlitic rail from ArcelorMittal Poland S.A. in the R260 grade. a) magn. 100x, b) magn. 500x.

Figure 12
Images of the microstructure of a fine-plate perlite rail of the ArcelorMittal Poland S.A. in the R350HT grade. a) magn. 100x, b) magn. 500x.

Figure 13
Images of the microstructure of (a) steel grade R260 and (b) steel grade R350HT (b).
Table 6
Hardness values for individual rails (HBW 2.5|187.5).
| Sample no. | Manufacturer | Steel grade | Hardness in the centre of the head, HBW | Hardness on the running surface, HBW | |||
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | mean | ||||
| 1 | Dortmunder Union | Low carbon steel | 204 | 192 | 189 | 195 | — |
| 2 | Phoenix West | Medium carbon steel | 168 | 171 | 165 | 168 | — |
| 3 | Aachener Hütte | Low carbon steel | 153 | 140 | 146 | 146 | — |
| 4 | KRUPP | Medium carbon steel | 198 | 205 | 198 | 200 | — |
| 5 | ArcelorMittal Poland S.A. | R260 | 274 | 271 | 279 | 275 | Avg. 285 |
| 6 | ArcelorMittal Poland S.A. | R350HT | 387 | 385 | 382 | 385 | Avg. 374 |

Figure 14
Baumann print, sample no. 1.

Figure 15
Baumann print, sample no. 2.

Figure 16
Baumann print, sample no. 3.

Figure 17
Baumann print, sample no. 4.

Figure 18
Baumann print, sample no. 5.

Figure 19
Baumann print, sample no. 6.

Figure 20
Etching test, sample no. 1.

Figure 21
Etching test, sample no. 2.

Figure 22
Etching test, sample no. 3.

Figure 23
Etching test, sample no. 4.

Figure 24
Etching test, sample no. 5.

Figure 25
Etching test, sample no. 6.

Figure 26
Image of a non-metallic inclusion – low carbon steel (Aachener Hütte), sample No. 3.

Figure 27
Mapping in the area of discontinuity – low carbon steel (Aachener Hütte), sample No. 3.

Figure 28
Location of the sample for assessing oxide cleanness in the rail head [9].
Table 7
Assessment of oxide cleanness.
| Sample no. | Area of the assessed surface (mm2) | Type of inclusions | Number of inclusions determined by the classification number | First subtotal | K3 | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 3 | 4 | 5 | 6 | 7 | 8 | |||||
| Factor f g | ||||||||||
| 0.5 | 1 | 2 | 5 | 10 | 20 | |||||
| 1 | 200 | OA | 1 | 0 | 0 | 0 | 0 | 0 | 0.5 | 60 |
| OS | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
| OG | 15 | 2 | 1 | 0 | 0 | 0 | 11.5 | |||
| 2 | 200 | OA | 0 | 0 | 1 | 0 | 0 | 0 | 2 | 42.5 |
| OS | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
| OG | 5 | 0 | 2 | 0 | 0 | 0 | 6.5 | |||
| 3 | 200 | OA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 120 |
| OS | 2 | 3 | 0 | 0 | 0 | 1 | 24 | |||
| OG | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
| 4 | 200 | OA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 25 |
| OS | 2 | 2 | 1 | 0 | 0 | 0 | 5 | |||
| OG | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
| 5 | 200 | OA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| OS | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
| OG | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
| 6 | 200 | OA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| OS | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||
| OG | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |||

Figure 29
R260 steel with MnS inclusions.

Figure 30
R350HT steel with MnS inclusions.