The present invention provides an apparatus for manufacturing a compound powder, a method for preparing an iron-boron powder mixture using the same, a boron alloy powder mixture and a method for preparing the same, a powder conjugate and a method for manufacturing the same, and a steel pipe and a method for producing the same. According to one aspect of the present invention, the method for preparing the boron alloy powder mixture comprises: a step of preparing a mixture powder in which a ferroboron powder and a target powder are mixed; and a de-boronizing step of de-boronizing at least a portion of the ferroboron powder while boronizing at least a portion of the target powder through a prescribed heat treatment so as to reduce the melting point of the ferroboron powder.
