Cast-in cemented carbide components

1. A compound body comprising:

cemented carbide including a cobalt binder phase,

wherein the cobalt binder phase has a magnetic cobalt content of 0.9 to 1.0 of the nominal cobalt content;

a low carbon steel surrounding the cemented carbide,

wherein the steel has a carbon content corresponding to a carbon equivalent Ceq=wt-% C+0.3(wt-% Si+wt-% P) of less than 0.9 wt-% but more than 0.5 wt-%, and

a transition zone between the cemented carbide and steel,

wherein the transition zone includes an eta-phase zone with a thickness between 50 and 200 μm,

wherein, in the cemented carbide adjacent to the eta-phase zone, there is an iron containing transition zone and

wherein, in the steel adjacent to the eta-phase zone, there is a zone with enriched carbon content.

2. The compound body of claim 1 wherein the carbon equivalent Ceq is less than 0.8 wt-%.

3. The compound body of claim 1 wherein the body is an earth moving tool, the cemented carbide has a binder phase content of from 10 to 20 wt-% Co and/or Ni with WC with a grain size between 0.5 and 7 μm.

4. The compound body of claim 1 wherein the body is a rock milling bit cutter, the cemented carbide has a binder phase content of from 9 to 15 wt-% Co and/or Ni in WC with a grain size between 2 and 10 μm.

5. The compound body of claim 1 wherein the body is a rock milling tool, the cemented carbide has a binder phase content of from 5 to 9 wt-% Co and/or Ni with WC with a grain size between 2 and 15 μm.

6. The compound body of claim 1 wherein the body is a crusher arm or a paddle in a crusher, the cemented carbide has a binder phase content of from 10 to 25 wt-% Co and/or Ni in WC with a grain size between 2 and 10 μm.

7. The compound body of claim 1 , wherein the iron containing transition zone has a width of from 0.5 to 2 mm.

8. The compound body of claim 1 , wherein the zone with enriched carbon content has a width of between 10 and 100 μm.

9. A compound body comprising:

cemented carbide including a cobalt binder phase,

wherein the cobalt binder phase has a magnetic cobalt content of 0.9 to 1.0 of the nominal cobalt content; and

a low carbon steel, wherein the steel has a carbon content corresponding to a carbon equivalent Ceq=wt-% C+0.3 (wt-% Si+wt-% P) of less than 0.8 wt-% but more than 0.5 wt-%,

wherein the steel surrounds the cemented carbide and the compound body further comprises:

a transition zone cemented carbide/steel including a thin eta-phase zone with a thickness between 50 and 200 μm,

in the cemented carbide adjacent to the eta-phase zone, an iron containing transition zone with a width of from 0.5 to 2 mm, and

in the steel adjacent to the eta-phase zone, a zone with enriched carbon content with a width of between 10 and 100 μm.

10. Method of casting a compound body, comprising:

fixing a cemented carbide part in a mold;

pouring melted steel into the mold to form a casting; and

cooling the casting in free air,

wherein the cemented carbide part includes a cobalt binder phase and wherein the cobalt binder phase has a magnetic cobalt content of 0.9 to 1.0 of the nominal cobalt content,

wherein the steel is a low carbon steel having a carbon content corresponding to a carbon equivalent Ceq=wt-% C+0.3(wt-% Si+wt-% P) of less than 0.9 wt-% but more than 0.5 wt-%,

wherein the temperature of the melted steel during the pouring is between from about 1550 to about 1650° C.,

wherein the method forms a transition zone between the cemented carbide and steel in the compound body,

wherein the transition zone includes an eta-phase zone with a thickness between 50 and 200 μm,

wherein, in the cemented carbide adjacent to the eta-phase zone, there is an iron containing transition zone, and

wherein, in the steel adjacent to the eta-phase zone, there is a zone with enriched carbon content.

11. The method of claim 10 wherein the carbon equivalent Ceq is less than 0.8 wt-%.

12. The method of claim 10 wherein a heat treatment is performed after the casting in order to harden and anneal the steel.