CrN coated steels assisted with a nano Cr interlayer were investigated. The Cr nano-interlayers were prepared by sputter deposition with a thickness about 70-100 nm. CrN coatings were also prepared by sputter deposition on the Cr nano-interlayers. The crystal structures, microhardness, and scratch resistance of CrN/Cr coatings were determined. Results show that the Cr nano-interlayers improve scratch resistance and the microhardness of CrN coated steels. A rapid heat treatment with infrared (IR) was performed for coated specimens in the attempt to improve bonding. With IR heat treatments, the beneficial effect of the Cr nano-interlayers was clearly observed. Without the Cr nano-interlayers, severe cracks on the surface of coatings were observed after IR heat treatment. However, with a Cr interlayer, no cracks on the surface of CrN coatings were observed after the heat treatment. The scratch resistance of coatings was also affected by the Cr nano-interlayers. The scratch track was clean and showed significantly smaller amount of scratch debris for CrN coatings with Cr interlayers than those without the Cr nano-interlayers. The microhardness of coatings with the Cr nano-interlayers is higher than those without the Cr nano-interlayers after IR heat treatment. The Cr and CrN phase have been identified with X-ray diffraction analysis, and the results show that the higher the nitrogen content in the sputtering gas, the stronger the CrN peaks observed in the diffraction patterns are. CrN coated steels assisted with a nano Cr interlayer were investigated. The Cr nano-interlayers were prepared by sputter deposition with a thickness about 70-100 nm. CrN coatings were also prepared by sputter deposition on the Cr nano-interlayers. The crystal structures, Results show that the Cr nano-interlayers improve scratch resistance and the microhardness of CrN coated steels. A rapid heat treatment with infrared (IR) was performed for coated specimens in the attempt to improve the bonding. With IR heat treatments, the beneficial effect of the Cr nano-interlayers was clearly observed. Without the Cr nano-interlayers, severe cracks on the surface of the coatings were observed after IR heat treatment. However, with a Cr interlayer, no cracks on the surface of CrN coatings were observed after the heat treatment. The scratch resistance of coatings was also affected by the Cr nano-interlayers. The scratch track was clean and showed significant variable amount of scratch debris for CrN coatings with Cr interlayers than those without the Cr nano-interlayers. The microhardness of coatings with the Cr nano-interlayers is higher than those without the Cr nano-interlayers after IR heat treatment. The Cr and CrN phase have been identified with X-ray diffraction analysis, and the results show that the higher the nitrogen content in the sputtering gas, the stronger the CrN peaks observed in the diffraction patterns are.