reported the cracking behavior of a Cr13Ni5Si2 coating on a carbon steel substrate. Huang and Zeng discussed the cracking of Ni-based coatings on carbon steel substrates. Generally, carbon steel substrates tend to contribute to the cracking of coatings. The cracking behavior of brittle coatings varies on different substrates. This is an ideal method to fabricate a high-hardness FeCoNiCrAl coating with a low dilution rate. The ultralow dilution of EHLA determines the stable chemical composition and mechanical properties of the coating. According to these investigations, the EHLA method has the advantages of high efficiency, ultralow dilution, and enhanced microstructure. also fabricated a FeCoNiCrMn HEA coating using the EHLA method. A special combination between the coating and substrate was observed. fabricated a 1Cr17Ni2 coating using the EHLA method. Their results showed that the corrosion resistance of the coating was enhanced. fabricated a 431 stainless steel coating on 27SiMn steel using the EHLA method. Their results showed that EHLA had an ultralow dilution rate. Lampa and Smirnov compared the microstructure of coatings fabricated using traditional laser cladding and EHLA. Based on the above discussion, to maintain the excellent properties of HEA coating, a cladding method with an ultralow dilution rate should be developed.Įxtreme high-speed laser cladding (EHLA) is a new technology with the advantage of higher efficiency. However, the uniformity and concentration of Fe in the coating could not be accurately controlled. In this experiment, the melted steel substrate was considered as the source of Fe in FeCoNiCrAlTi HEA coating. ingeniously used the dilution to fabricated a FeCoNiCrAlTi HEA coating and characterized its corrosion behavior. However, the cladding the buffer layer reduced the efficiency. The results showed that the FeCoCrNiMnAl 0.5 buffer Layer effectively hindered the dilution of FeCoCrNiMnAl surface coating. developed the laser cladding process and fabricated a FeCoCrNiMnAl gradient HEA coating on steel. In order to avoid the negative effect from dilution, Cui et al. The large dilution rate contributed to the generation of an FCC phase in the coating and decreased the hardness to only approximately 200 HV. However, an inappropriate process in this investigation resulted in a large dilution rate of the coating. fabricated a FeCoNiCrAl HEA coating on Q235 carbon steel. revealed that the laser cladded FeCoNiCrAl HEA coating had a dilution rate larger than 35%. However, severe dilution of coating was hard to be avoided. With the advantages of HEAs and the development of laser cladding technology, HEAs have been successfully coated on steel using laser cladding. revealed that the high-hardness character of FeCoNiCrAl HEAs was maintained after a laser deposition process. Their results showed that the FeCoNiCrAl HEA achieved a hardness higher than 500 HV. investigated the effect of Al addition on the microstructure and hardness of FeCoNiCrAl x HEAs. As a martensitic transformation did not occur in 304SS, the low-hardness substrate effectively relieved the tensile stress in the coating and avoided cracking.Ī FeCoNiCrAl high entropy alloy (HEA) with an equal atomic ratio has a high hardness. This restricted the plastic deformation of the substrate and increased the tensile stress and cracking tendency of the coating. The finite element method showed that the martensite transformation of C45 expanded the volume and increased the hardness of the HAZ. The martensitic transformation of the heat-affected zone (HAZ) of the C45 substrate was considered the main factor contributing to cracking of the coating. The C45 substrate showed a remarkable effect on the cracking of the coating. The results showed the high-hardness character of the two coatings on C45 and 304SS substrates. In this work, FeCoNiCrAl coatings on C45 carbon steel and 304 stainless steel (304SS) pipes were fabricated using extreme high-speed laser cladding (EHLA) with a cladding speed of 50 m/min. However, the brittle nature always contributes to the cracking of the equiatomic FeCoNiCrAl HEA coating. FeCoNiCrAl high entropy alloys (HEAs) are regarded as promising coating materials for traditional steel.