Analysis on the Operation Methods of Rail Welding and Postweld Heat Treatment in the Track Change Overhaul of Existing Railway Lines

Based on the analysis of operation methods of rail welding and postweld heat treatment in the track change overhaul of existing railway lines at home and abroad, this paper puts forward the existing problems in the operation methods of off-line welding and on-line welding in China, and puts forward the solutions to the existing problems. When this operation mode is used for on-line welding, it can reduce the quality risk in the heat treatment process of low-temperature locking joint; in case of broken track and urgent repair of broken track, this method can eliminate secondary shunting and facilitate the recovery of the line as soon as possible.

Structural and Tribological Properties of Heat-Treated Stainless Steels against Abrasive and Lubricant Wear Conditions

The current paper investigates the effect of the heat treatment process on three grades of stainless steel alloys against the abrasive and the lubricant wear conditions, using 25 wt.% glucose solution for the industrial agriculture applications. The heat treatment process was carried out for one hour at 900 ± 10 °C, followed by quenching with monograde motor oil and tempering for more than two hours at 200 ± 10 °C. Several analyses were conducted to estimate the final mechanical, surface morphological and tribological properties for the studied materials, before and after the heat treatment process. The heat-treated martensitic stainless steel grade exhibited superior wear resistance and higher hydrophobicity compared to the other two heat-treated austenite stainless steel grades. Therefore, the mechanism of the heat treatment process, the chemical and physical nature of the parent material, and the viscosity of the selected lubricant all influence the final behaviour of the studied material against the applied operating conditions for the selected application.