The present invention relates to coated metal substrates such as metal piping having improved environmental stress crack resistance and resistance to hydrolytic and/or cathodic disbondment. The coating composition contains a blend of modified and unmodified polyolefins as well as a tackifier. For cathodic disbondment resistance, the preferred tackifiers are rosin esters or hydrogenated versions thereof. The modified polyolefins are grafted versions of metallocene or non-metallocene produced low density or high density polyethylenes.