A method for joining a first metal part (11) with a second metal part (12), the metal parts (11, 12) having a solidus temperature above 1000 DEG C. The method comprises: applying a melting depressant composition (14) on a surface (15) of the first metal part (11), the melting depressant composition (14) comprising a melting depressant component that comprises phosphorus and silicon for decreasing a melting temperature of the first metal part (11); bringing (202) the second metal part (12) into contact with the melting depressant composition (14) at a contact point (16) on said surface (15); heating the first and second metal parts (11, 12) to a temperature above 1000 DEG C; and allowing a melted metal layer (210) of the first metal component (11) to solidify, such that a joint (25) is obtained at the contact point (16). The melting depressant composition and related products are also described.