An American steel from Carpenter, CTS-XHP is a stainless steel with great edge retention. You can almost think of it like D2, but with more corrosion resistance. It can be difficult to sharpen and like D2 it can be a little and prone to chipping on the edge.
Carbon (C) 1.60%, Chromium (Cr) 16.00%, Manganese (Mn) 0.50%, Molybdenum (Mo) 0.80%, Nickel (Ni) 0.35%, Silicon (Si) 0.40%, Vanadium (V) 0.45%. Typical Rockwell of 58-60 Rc.