本申请涉及一种药芯带芯钎焊环、钎焊双环组合件及其使用方法，药芯带芯钎焊环由药芯钎料带围成的管状结构内包含一根钎料芯丝，药芯钎料带两侧末端与钎料芯丝连接，药芯钎料带与钎料芯丝之间空腔填充钎剂。药芯带芯钎焊环的外侧和或内侧为环状扁平面。钎焊双环组合件由上述药芯带芯钎焊环和内侧有对接缝隙的药芯扁环配合构成，药芯带芯钎焊环内侧为环状扁平面。药芯带芯钎焊环的药芯钎料带两侧末端与钎料芯丝连接处朝外或朝下。本申请结构简洁，通过药芯带芯钎焊环的连接处缝隙以及药芯扁环的对接缝隙，在避免钎剂和空气接触反应的同时提高钎料和母材接触面及热传导效率，钎剂在加热反应后从缝隙中流出，优先到达母材表面，达到钎剂优先反应的效果。

The invention relates to a flux-cored brazing ring, a brazing double-ring combined part and an application of the flux-cored brazing ring and the brazing double-ring combined part. According to the flux-cored brazing ring, a solder core wire is contained inside a tubular structure which is defined by a flux-cored solder strip; the tail ends of the two sides of the flux-cored solder strip are connected with the solder core wire; and a cavity between the flux-core solder strip and the solder core wire is filled with brazing flux. The outer side or the inner side of the flux-core brazing ring isan annular flat surface. The brazing double-ring combined part is composed of the flux-cored brazing ring and a flux-cored flat ring which are matched with each other, wherein the inner side of the flux-cored flat ring is provided with a butting gap; and the inner side of the flux-cored brazing ring is an annular flat surface. The joints of the solder core wire and the tail ends of the two sides of the flux-cored solder strip of the flux-cored brazing ring are outward or downward. The flux-cored brazing ring and the brazing double-ring combined part provided by the invention are concise in structure; by a gap in the joint of the flux-cored brazing ring and the butting gap of the flux-cored flat ring, contact reaction of the brazing flux and the air is prevented, meanwhile the contact surface of solders and a base material is increased and the heat transfer efficiency is improved; and the brazing flux flows out of the gaps after heating reaction is ended and preferentially reaches the surface of the base material, so a preferential reaction effect of the brazing flux is achieved.