Low Temperature Fatigue Behavior of Steels - A Review

Fatigue Fract Eng Mat Struct

et al. 2019

The fatigue crack growth rate (FCGR) of ER8C high‐speed railway wheel rim material was tested at various service temperatures. The temperature sensitivity of fatigue crack propagation was evaluated, and the effect of temperature on the crack propagation mechanism was analyzed. The obtained results indicate a fatigue ductile‐to‐brittle transition (FDBT) point at −20°C for the ER8C wheel rim materials. A reverse relationship was found between FCGR and temperature for the near threshold and Paris regimes when the temperature was below the FDBT point. However, no evident changing rule was found when the temperature was above this transition point. An evident fatigue crack propagation mode transition was found from lamellar tearing to intergranular cracks, which was related to the FDBT for the near‐threshold regime.

Section: Resultssupporting

confidence: 90%

“…However, the FCGR increased with decreasing temperature for the Paris regime, as shown in Figure 4. This was consistent with the results of Stephens et al 21…”

Section: Microstructure Characterizationsupporting

confidence: 94%

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Evaluation of temperature‐sensitive fatigue crack propagation of a high‐speed railway wheel rim material

Fang

Cai

Fatigue Fract Eng Mat Struct

et al. 2019

“…In general, the fatigue crack propagation rate of ferritic steels, which have the stable body-centered-cubic lattice, decreases with the descent of temperatures until the ductile striation mode of fatigue crack propagation mechanism converts into cyclic cleavage, [13][14][15] which indicates the occurrence of fatigue ductile-to-brittle transition. Below the fatigue ductile-to-brittle transition temperature, fatigue crack propagation rate increases with the decreasing temperature.…”

Section: Introductionmentioning

confidence: 99%

Fatigue crack propagation for Q345qD bridge steel and its butt welds at low temperatures

Liao

Fatigue Fract Eng Mat Struct

Qian

et al. 2017

Steel bridges fabricated with Q345qD steels face critical challenges when operating in cold regions with a low ambient temperature. This study aims to investigate, via an experimental program, the low‐temperature fatigue crack propagation behavior of Q345qD bridge steel base material and its butt welds. The testing program comprises a series of Charpy impact tests and fatigue crack propagation tests at the room temperature, −20°C and −60°C. The experimental results demonstrate a reduced crack propagation rate in the base material, but an increasing crack propagation rate in the butt welds, with a decreasing ambient temperature. The base material also shows enhanced fatigue crack propagation thresholds with the decreasing temperature. The ductile‐to‐brittle transition temperature for fatigue is lower than that for fracture in the base material while the weld metal exhibits an opposite trend. Generally, the butt welds present higher resistance against fatigue crack propagation and larger Charpy toughness values than do the base material at all tested temperatures. The Paris‐law parameters measured at the room temperature for the base material leads to a conservative assessment of the crack propagation life for a welded joint under a low ambient temperature.

“…Shank et al investigated many accidents and found that the change of steel's notch sensitivity was the main cause of accidents that occurred at extreme temperatures [13]. It was also found that with the gradual decrease of temperature, fractures in railway material will change from the ductile shear fracture mode to the brittle cleavage fracture mode, causing the decline of fracture toughness, impact energy, and plasticity [14][15][16][17][18]. Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Study on Wear and Fatigue Performance of Two Types of High-Speed Railway Wheel Materials at Different Ambient Temperatures

Guo

et al. 2020

Materials

The wear and fatigue behaviors of two newly developed types of high-speed railway wheel materials (named D1 and D2) were studied using the WR-1 wheel/rail rolling–sliding wear simulation device at high temperature (50 °C), room temperature (20 °C), and low temperature (−30 °C). The results showed that wear loss, surface hardening, and fatigue damage of the wheel and rail materials at high temperature (50 °C) and low temperature (−30 °C) were greater than at room temperature, showing the highest values at low temperature. With high Si and V content refining the pearlite lamellar spacing, D2 presented better resistance to wear and fatigue than D1. Generally, D2 wheel material appears more suitable for high-speed railway wheels.