Microstructure and Performance of Fe-Based Composite Clad Layer Fabricateded by Submerged-Arc Welding Added Alloy Powder

Abstract

TiC particle reinforced Fe-based composite clad layer were in situ synthesized on surface of Q235 steel by Submerged arc Welding of the mixed powder of ferrotitanium, iron, chromium, nickel and colloidal graphite, etc. Microstructure of the clad layer were observed by scanning electron microscope （SEM） and Energy Disperse Spectroscopy (EDS). Wear resistance of the clad layer was tested on wear tester at room temperature compared with the base material Q235 steel. Microhardness of the clad layer was measured by microhardness tester. Results indicated that the fine TiC particles were formed by Submerged-arc Welding process, and the the TiC particles were dispersed in the matrix. The size of TiC particles was less than 2 μm. The microstructure of cladding layer consisted of TiC particles, martensite and austenite. The average microhardness of clad layer was HV0.2601, which was about 3 times as high as the based metal Q235. On the conditions of same wear and room temperature, the weight loss of the base material Q235 is 10-15 times as much as the composite clad layer. The weight loss increase of the clad layer has a little change with the increase of load and the change of load is not sensitive to the weight loss of the clad layer. The clad layer has good load characteristics.