The best place I know of to look is the ASM bookstore. The ASM Handbooks have huge data bases of metallurgical data like what your are asking about. And there are others. The problem will be the specificity of your question. And unless you have prior access it will be difficult to determine exaclty which volume will have your specific diagram. Evne though these volumes will have many sensitization diagrams the overwhelming number of alloys is prohibitive in providing the diagrams for everything. But ASM is the best place to start. Maybe The Metallurgical Society. TMS. You might even give them a call and see if they can help you find the volume you need.