Effect of Cr₃C₂ content on microstructure and properties of 310 stainless steel coating by PTA welding

ABSTRACT

In this work, the effect of Cr₃C₂ on the microstructure and properties of 310 coatings by plasma transfer arc welding was studied. The microstructure, composition, hardness and wear resistance of the coatings were analyzed by scanning electron microscope, EDS, X-ray diffractometer, microhardness tester and friction wear tester. The results show that when Cr₃C₂ is less, the coating is composed of columnar crystal and cellular crystal, mainly including (Fe, Ni) Fe₃Ni₂FeCr_0.29Ni_0.16C_0.06Cr₂Fe₁₄C and CrFe₇C_0.45. With the increase of Cr₃C₂, the structure becomes dendrites and new phases Cr₇C₃ and Cr₂₃C₆ appeared. However, the crystallinity of 5% is poor and there is no obvious grain structure. The hardness of the coatings increases first and then decreases with the content of Cr₃C₂. The hardness with the content of 3% is the highest. The friction coefficient corresponds to the hardness and the main wear mechanism is abrasive wear and oxidation wear.

KEYWORDS:

• Cr₃C₂/310 coatings
• microstructure
• microhardness
• wear resistance

Disclosure statement

No potential conflict of interest was reported by the author(s).