Abstract: The present disclosure relates to a method of making a cemented carbide mining insert, a cemented carbide mining insert with having a chemical and hardness gradient and to the use thereof. The method includes the steps of providing a green mining insert compact formed from a first powder including a WC-based hard phase, optionally one or more further hard-phase components and a binder, applying a second powder including a grain refiner compound and/or a carbon based grain growth promoter to at least one portion of a surface of the green mining insert compac, and sintering the green mining insert compact to produce a cemented carbide mining insert, wherein the first powder additionally includes Cr, in an amount such that the mass ratio of Cr/binder is of 0.01-0.3.

Abstract: A rock drill insert made of cemented carbide includes hard constituents of tungsten carbide (WC) in a binder phase of Ni—Cr, or Ni—Co—Cr, and a balance of WC and unavoidable impurities. The cemented carbide has a 3.5-18 wt % binder phase. The binder phase has >0 wt % Ni. The mass ratio Cr/(Ni+Co) is 0.02-0.19. A difference between the hardness at 0.3 mm depth at some point of the surface of the rock drill insert and the minimum hardness of the bulk of the rock drill insert is at least 30 HV3.