I am a draftsman. I make project of mechanical pieces and machinery. Some pieces works like knifes or sleeve, so to reduce the friction we design the ideal material to manufacture this pieces. The steel Vc 130 or 131 are options of choices. What is the usage of steel grades VC-130 and VC-131? What the difference in applications between them, on tools and gears projects?
VC-130 and VC-131 are names from the Brazilian standard. A comparison can be found at Paulo Sergio's website. Table 4 suggests that VC-130 is equivalent to AISI-D3 and VC-131 is equivalent to AISI-D6. However, these stainless steels are low sulfur (see the Villares VC-131 page). I think the "Tool & Die Steels" site has the composition wrong.
The main difference between the two steels is the Tungsten content. Tungsten tends to reduce pitting corrosion (see the Outokompu page).