Brazing clad material, and brazing method and brazing product using the same

A brazing product, comprising:

• a brazing clad material, comprising:
• a composite material that comprises a base material and a brazing material layer formed integrally on the base material,
• wherein the brazing material layer comprises a Ni or Ni alloy layer, a Ti or Ti alloy layer and a Fe—Ni alloy layer that are sequentially stacked in this order on the base material,
• wherein the brazing material layer comprises a Fe concentration of 25 to 40 wt % in the entire brazing material layer,
• wherein the brazing material layer satisfies a ratio of W1/W2 to be 0.56 to 0.66, where W1 is a weight of Ni contained in the entire brazing material layer and W2 is a total weight of Ni and Ti contained in the entire brazing material layer,
• wherein the brazing material layer comprises a diffusion reacting layer with a thickness of 2 to 6 μm,
• wherein the diffusion reacting layer is formed at an interface between two hetero-metals of the Ni or Ni alloy layer, the Ti or Ti alloy layer and the Fe—Ni alloy layer to compose the brazing material layer, and
• wherein the brazing clad material is brazed to the brazed member by a method comprising the steps of:
• preheating the brazing clad material at a temperature of 800 to 940° C. and
• brazing the preheated brazing clad material to the brazed member in a vacuum atmosphere at a temperature of 1100 to 1200° C.