The invention discloses a carbon-controlling and
toughening type self-shielded open-arc high-
boron surfacing flux-cored wire. According to the technical scheme, a low-carbon-steel H08A cold-rolled thin steel strip is adopted as an outer sheath, and an
alloy,
graphite and other
metal powder are mixed in the sheath to form a
powder core, wherein the surfacing
alloy is
alloy powder obtained by adding high-content ferro-
boron, high-carbon
ferrochrome and
ferrotitanium with different melting properties into the flux-cored wire; by virtue of open-arc surfacing current control, a high-
boron surfacing melt with the alloy component in an incompletely-molten and unevenly-mixed state is formed, so that an
alloy element phase structure is selectively optimized and configured; the powder core mainly consists of the following components: ferro-boron, high-carbon
ferrochrome,
ferrotitanium,
graphite, medium-carbon
ferromanganese,
ferrosilicon and reduced
iron powder. The carbon-controlling and
toughening type self-shielded open-arc high-boron surfacing flux-cored wire overcomes the defect that a current high-boron surfacing alloy is great in
brittleness due to
microstructure characteristics of the high-boron surfacing alloy, can be widely applied to surfacing manufacturing or repairing of parts with
abrasive wear resistance, for example, a concrete
cement conveying tube, and is especially suitable for surfacing manufacturing or paring of the parts with low-stress
abrasive wear resistance.