Abstract:
A kind of Fe-Cr-W-Nb high-temperature wear-resistant flux-cored wire was designed, and the cladding layer was prepared on the surface of Q235 steel matrix by submerged arc surfacing technology under different surfacing currents (350, 400, 450, 500 A)., The effects of surfacing current on the microstructure, microhardness and high temperature wear resistance of the cladding layer were studied. The results show that the cladding layers prepared by different surfacing currents were mainly composed of Fe-Cr solid solution, M
23C
6, NbC and a small amount of M
7C
3 and Fe
3W
3C. With the increase of surfacing current, the growth of NbC hard phase particles was gradually sufficient. When the surfacing current was 450 A, the hard phase particles of the cladding layer grew most fully, and the size was consistent, the distribution was uniform, and the cladding layer formed a good metallurgical bond with the steel matrix. When the surfacing current was too large (500 A), the hard phase particles were connected to each other to form an irregular shape, and the size was obviously coarse and and the distribution was uneven. With the increase of the surfacing current, the average microhardness of the cladding layer first increased and then decreaseds, and the wear quality loss first decreased and then increased. When the surfacing current was 450 A, the average microhardness was the largest, the wear loss was the smallest, and the wear resistance was the best, and the wear mechanism was oxidative wear.