**1. Introduction**

Copper accumulates in steel when steel scrap is reused, because it is difficult to remove copper in steelmaking processes [1]. Therefore, with the increase in the amount of scrap steel being used, it is imperative to study the application of copper in copper-bearing steels. Meanwhile, much research has been done to produce copper cladding on a steel surface using various methods. Copper, with its unique physical, chemical, mechanical, and physiological properties, has an important role in the lives of humans, and it also has an important application in many industrial and technical fields. Copper has been used both as an intermediate or undercoating, and as a top coat material [2].

Steel/copper clad metals are widely studied because they have applications ranging from functional coatings in the electrical and electronics industries, to adhesion promoting coatings, intermediate coatings for improving brightness and leveling effects in decorative/corrosion-protective coating systems, and purely decorative uses as a top coating [3,4]. Electroplating and electroless plating [2,5], cladding [6,7], cold sprayed coating [8–10], and casting [11] approaches have been widely used to produce copper-clad steel. Composite materials are more difficult to produce than single materials because of the diversity of their material properties. According to the characteristics that copper in copper-bearing steels, such as weathering steels, are easy to segregate on the surface of steels, accelerated corrosion tests of copper-bearing steels at 25 ◦C (room temperature)

**Citation:** Li, N.; Yan, L.; Wang, S.; Wang, C.; Zhang, H.; Ai, F.; Jiang, Z. Corrosion Behavior of Copper Bearing Steels and the Derived In-Situ Coating. *Metals* **2021**, *11*, 1462.https://doi.org/10.3390/met11091462

Academic Editor: Renato Altobelli Antunes

Received: 1 August 2021 Accepted: 13 September 2021 Published: 15 September 2021

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were carried out in this study in order to make copper-clad steel composites. A nearly perfect in-situ copper coating was observed after the rusts was removed from the corroded copper-bearing steels. As one of the basic properties of cladding material, the corrosion resistance of the copper-coated steels was tested by electrochemical corrosion test.

#### **2. Materials and Methods**
