Which parts of the boiler are prone to grooves? What are the causes of grooves?

This post was last edited by zgj2405 on 2011-9-26 13:33 1. The flange where the head of a vertical water tube boiler is connected to the pot shell and the flange where the head is connected to the cupola are prone to grooves. The main reasons are that the radius of the edge arc is too small, the processing stress is too large, and the steel plate is thinned, plus the alternating stress caused by temperature and stress changes. It has low fatigue damage properties. The cracks are circumferential and generally have multiple parallel cracks. When the crack occurs for a long time, due to the action of alternating stress, the cracked material is squeezed and the main crack is relatively thick, so it is called "grooving". 2. For horizontal shell boilers and flat-head boilers, grooves are easily formed at the connection between the furnace flange and the front head. At the connection between the edge of the furnace and the front head, in addition, due to the furnace heating and shutting down, periodic coal addition, ash removal, large amounts of cold air infiltration, and sudden cooling and heating of the furnace, periodic expansion and contraction movements occur, resulting in great alternating stress. These stresses are concentratedly reflected on the flange of the furnace reinforcement ring. If the flange arc is too small, fatigue cracks will easily occur. Small fatigue cracks begin to occur. Due to the erosion of the pot water, electrochemical corrosion occurs and gradually develops into grooves.