Welding method for Y-shaped groove and welded assembly

The invention relates to the technical field of welding and provides a welding method for a Y-shaped groove. The welding method for the Y-shaped groove includes the following steps that the Y-shaped groove is formed in the welding position of each of two to-be-welded parts which are 10-26 mm thick; the two to-be-welded parts are preheated to 210-230 DEG C; welding is carried out when the temperature of the to-be-welded parts reaches 210-230 DEG C, heat preservation is conducted on the to-be-welded parts in the welding process, and the temperature of the to-be-welded parts is kept at 210-230 DEG C; cooling is carried out after welding is completed, the temperature decreasing rate of the welding positions is controlled to be 230-500 DEG C/h, heat preservation is still conducted on a welded assembly, and the maintained temperature is 210-230 DEG C; and heat preservation is stopped when the temperature of the welding positions is decreased to 210-230 DEG C, and the temperature decreasing rate is controlled to be