Due to the rapidly expanding practice of recycling used metals it makes me curious to know if, for example, recycled carbon steel is the same exact physical and chemical material it was before it was recycled. Or do recyclers have to add processes and carbon, etc. to get it back the exact material and performance specs it had before? For example, if an old car's steel was melted down each day for a thousand days, ten thousand days, or a million days in a row, would it be substantially the same material afterward each time as it was before the very first smeltering? Or, would additional processes and metals, chemicals, carbon, etc. have to be added each/over time to insure the steel maintained the exact metalurgical and physical qualities such as composition, strength, hardness, durability, flexibility, etc. it had after initial smeltering? I may have omitted some tech terms or words or used incorrect layman definitions in the above, but you get the idea, and thanks so much for all informed and detailed answers that will explain the process and results to a layman.