Fe-Cr-C-B-Ti-B

4

C wear resistant surfacing layer is prepared on Q235 substrate by automatic CO

2

gas shielded welding.Microstructure and performance of the surfacing layer are studied by metallographic microscope

X ray diffractometer

hardness tester and abrasive wear machine. The results show that addition of B

4

C has significant effect on the variety

morphology and quantity of the microstructure

which further affects the hardness and wear resistance of the surfacing layer. The microstructure of surfacing layer without B

4

C is composed of needle-type martensite

retained austenite and eutectic structure;and after adding B

4

C

the microstructure of surfacing layer is cellular primary austenite and eutectic structure. With the increase of B

4

C content

the hardness of the surfacing layer improves gradually

while its wear loss increases firstly and then decreased. When the content of B

4

C is 20%

the wear resistance of the surfacing layer is the best.