Well it could be a heat treat problem but what was the knife used for to cause all the chipping? I just looked at Bob Dozier's website. He is one of the best makers using D2 and he heat treats 60-61 Rc on all his blades, blades 2.5" up to one I saw that was 6". The 59 Rc you talk about seems reasonable to me (I'm no expert). I have seen other makers treat at 58-59Rc. Again, D2 is "generally" not considered good for larger combat type knives that will have blade to blade contact, or a knife that will be used to pry. I love D2 for a hunting knife. Hope this helps.