SLD steel by Hitachi is an excellent steel for kitchen knives. The base of the steel is SKD11 in JIS ( = Japanese Industrial Standard ) mainly used for dies fit for punching or stamping. The main features of the steel is hard, tough and strong against wearing. Hitachi has improved it for better work and longer life, and named it SLD. The main chemical compositions of it is : C 1.4-1.6%, Cr 11.0-13.0%, Mo 0.8-1.2% & V 0.2-0.50%. Generally the steels which contain Cr 13.0% or more are called stainless steel. SLD has close to 13.% Cr and are fairly resistant for rust. Due to high carbon like 1.5%, the HRC after heat-treating reaches about 60point. I have not checked the real HRC of this SLD but due to forging, can expect 1-2 or 3point higher. Furthermore, by combined with Cr, carbon makes and forms what it is called the primary carbide with HV ( = Vickers ) 1,800-2,000 hardness, equivalent to HRc 62-63.
If you have a chance to see the micro-structure, you will see many white tiny grains spread. The primary carbides are actually much higher in HRC (about 80 HRC) so this adds to excellent wear resistance of the steel. If you look at the photo below you can see the carbides mixed into the steel. So even though the whole hardness is HRC 60 for instance, while actually used or sharpened, I think that you will feel and experience the difference.
For users who want AS-like cutting performance with excellent wear resistance against rust at a reasonable price, this SLD steel would be an excellent choice.