Rail surface grinding classification

Rail grinding is an important means to maintain the condition of rails, which is mainly divided into line rail grinding and turnout rail grinding. According to different purposes and timings, it can be divided into pre-grinding, preventive grinding and repair grinding.

Pre-grinding is mainly aimed at newly laid rails, aiming to remove the decarburized layer on the rail surface, correct the rail head profile, and improve the smoothness of the welded joints. This link is crucial for new lines and lines where new rails are laid in sections.

Preventive grinding is the regular grinding of rails, aiming to repair the rail head profile and eliminate shallow defects such as microcracks, thereby preventing the occurrence of deeper defects such as rail fatigue cracks and corrugation. High-speed railways generally carry out preventive grinding every 30Mt to 50Mt of total mass, while conventional railways formulate grinding plans based on curve radius, side grinding and damage.

Repair grinding is the grinding of damaged rails, which aims to correct the rail head profile and eliminate or reduce rolling contact fatigue cracks, wave (corrugation) wear and abrasions. This is a key link to keep the rails in good condition and extend their service life.