Abstract: The present invention relates to a cutting insert for a rock drill bit. The rock drill bit includes a tool body (10) having a front surface (13), and a number of cutting inserts (14), each having a generally cylindrical shank portion. The cutting insert (14) is provided with increased volume portions in its parts being most subjected to wear. The invention also relates to the rock drill bit.

Abstract: The present invention relates to a cutting insert for a rock drill bit and a rock drill bit including such a cutting insert. It has the object of increasing the wear resistance of the cemented carbide cutting insert. The inserts are formed with a generally cylindrical shank portion and a convexly formed outer portion. In one embodiment of the invention, the cemented carbide of the insert includes a number of zones and the border between two adjacent zones describes a non-symmetrical path seen both in a cross-sectional side view and in a cross-sectional top view. In a further embodiment, the inserts are also provided with increased volume portions in the parts of the insert being most subjected to wear.

Abstract: There is now provided a cemented carbide button for rock drilling comprising a core and a surface zone surrounding the core whereby both the surface zone and the core contains WC (.alpha.-phase) and a binder phase based on at least one of cobalt, nickel or iron and that the core in addition contains .eta.-phase. In addition, in the inner part of the surface zone situated close to the core, the cobalt content is higher than the nominal content of cobalt and the cobalt content in the outermost part of the surface zone is lower than the nominal and increases in the direction towards the core, up to a maximum usually at the .eta.-phase core. The grain size distribution of the hard constituent in the zone with high cobalt content and in the .eta.-phase core is narrow in contrast to a button of the prior art in which the grain size distribution of the hard constituent in the zone with high cobalt content and the .eta.-phase core is wide.

Abstract: The present invention relates to cemented carbide bodies preferably for rock drilling and mineral cutting. Due to the fact that the bodies are built up of a core of eta-phase-containing cemented carbide surrounded by a surface zone free of eta-phase with low Co-content in the surface zone and successively increasing Co-content to a maximum in the outer part of the eta-phase-core they have obtained an increase in toughness and life at practical use.

Abstract: A cemented carbide button for rock drilling comprises a core and a surface zone surrounding the core whereby both the surface zone and the core contains WC (alpha-phase) and a binder phase based on at least one of Co, Ni, or Fe and the core in addition contains eta-phase. The eta-phase core extends to the very top (working) surface of the button and as a result is obtained longer life and higher drilling rate particularly for rotating crushing drilling, cutting drilling and percussive drilling in soft rocks.

Abstract: The present invention relates to cemented carbide bodies preferably for wear demanding rock drilling and mineral cutting. The bodies are built up of a core of eta-phase-containing cemented carbide surrounded by a surface zone free of eta-phase where the binder phase content in the outer pan of said zone is lower than the nominal and, in addition, constant or near constant, and the binder phase content in the inner part of the eta-phase free zone closer to the eta-phase core is higher than the nominal. According to the method of the invention, bodies comprising evenly distributed eta-phase are subjected to a partly carburizing treatment with a carbon activity, a.sub.c, close to 1.

Abstract: The present invention relates to cemented carbide bodies preferably for wear demanding rock drilling and mineral cutting. The bodies are built up of a core of eta-phase-containing cemented carbide surrounded by a surface zone free of eta-phase where the binder phase content in the outer part of said zone is lower than the nominal and, in addition, constant or near constant, and the binder phase content in the inner part of the eta-phase free zone closer to the eta-phase core is higher than the nominal. According to the method of the invention, bodies comprising evenly distributed eta-phase are subjected to a partly carburizing treatment with a carbon activity, a.sub.c, close to 1.

Abstract: The present invention relates to cemented carbide bodies preferably for rock drilling and mineral cutting. Due to the fact that the bodies are built up of a core of eta-phase-containing cemented carbide surrounded by a surface zone free of eta-phase with low Co-content in the surface zone and successively increasing Co-content to a maximum in the outer part of the eta-phase-core they have obtained an increase in toughness and life at practical use.