Cutting tool insert
Abstract
The present invention relates to a cutting tool insert for side and face milling of rolled low alloyed steel at low and at moderate cutting speeds comprising a cemented carbide body and a coating and a method for making same. The cemented carbide body comprises WC, from about 7.3 to about 7.9 wt-% Co and from about 1.0 to about 1.8 wt-% cubic carbides of Ta and Nb and a highly W-alloyed binder phase with a CW-ratio of from about 0.86 to about 0.94. The coating comprises: a first (innermost) layer of TiC x N y O z with a thickness of from about 0.1 to about 2 μm, and with equiaxed grains with size less than about 0.5 μm a layer of TiC x N y O z with a thickness of from about 2 to about 10 μm with columnar grains with a diameter of about less than about 5 μm a layer of TiC x N y O z with a thickness of 0.1-2 μm and with equiaxed or needlelike grains with size less than about 0.5 μm an outer layer of a smooth, textured, finegrained α-Al 2 O 3 layer with a thickness of from about 2 to about 10 μm. The invention also relates to the use of such a cutting tool insert for side and face milling of rolled low alloyed steel at low and moderate cutting speeds.
Claims
exact text as granted — not AI-modified1 - 8 . (canceled)
9 . A method of manufacturing a metal workpiece with a cutting tool insert including a cemented carbide body and a coating,
said cemented carbide body comprising WC, from about 7.3 to about 7.9 wt-% Co and from about 1.0 to about 1.8 wt-% cubic carbides of Ta and Nb, a highly W-alloyed binder phase with a CW-ratio of from about 0.86 to about 0.94, and an edge radius of from about 20 to about 45 μm, said coating comprising
a first (innermost) layer of TiC x N y O z with a thickness of from about 0.1 to about 2 μm, and with equiaxed grains with size less than about 0.5 μm,
a layer of TiC x N y O z with a thickness of from about 2 to about 10 μm with columnar grains with a diameter of less than about 5 μm,
a layer of TiC x N y O z with a thickness of from about 0.1 to about 2 μm and with equiaxed or needlelike grains with size less than about 0.5 μm, and
an outer layer of a smooth, textured, finegrained α-Al 2 O 3 layer with a thickness of from about 2 to about 10 μm,
the method comprising:
side and face milling the metal workpiece at low or moderate cutting speeds.
10 . The method of claim 9 , wherein the metal workpiece is formed of rolled low alloyed steel.
11 . The method of claim 9 , wherein the metal workpiece is a plate.
12 . The method of claim 11 , comprising manufacturing a tube from the milled plate.
13 . The method of claim 1 , wherein the α-Al 2 O 3 layer has a texture in the (104)-direction with a texture coefficient TC(104) larger than 1.3.
14 . The method of claim 1 , wherein the α-Al 2 O 3 layer has a texture in the (110)-direction with a texture coefficient TC(110) larger than 1.3.
15 . The method of claim 1 , wherein the cutting tool insert includes from about 0.5 to about 1.0 μm thick layer of TiN having a surface roughness R max <0.4 μm over a length of 10 μm and reduced in thickness over the edge line to from about 50 to about 90% of the thickness on the rake face.
16 . The method of claim 1 , wherein the cemented carbide includes from about 1.4 to about 1.7 wt-% carbides of Ta and Nb.
17 . A method of manufacturing a metal workpiece with a cutting tool insert, the cutting tool insert including a cemented carbide body and a coating,
wherein said cemented carbide body includes WC, from about 7.3 to about 7.9 wt-% Co and from about 1.0 to about 1.8 wt-% cubic carbides of Ta and Nb, a highly W-alloyed binder phase with a CW-ratio of from about 0.86 to about 0.94, and wherein said coating includes
a first (innermost) layer of TiC x N y O z with a thickness of from about 0.1 to about 2 μm, and with equiaxed grains with size less than about 0.5 μm,
a second layer of TiC x N y O z with a thickness of from about 2 to about 10 μm with columnar grains with a diameter of less than about 5 μm,
a third layer of TiC x N y O z with a thickness of from about 0.1 to about 2 μm and with equiaxed or needlelike grains with size less than about 0.5 μm,
an outer layer of a smooth, textured, finegrained α-Al 2 O 3 layer with a thickness of from about 2 to about 10 μm, and
a further layer of TiN having a surface roughness R max <0.4 μm over a length of 10 μm, having a thickness on a rake face of from about 0.5 to about 1.0 μm and having a reduced thickness over an edge line of from about 50 to about 90% of the thickness on the rake face,
the method comprising:
side and face milling the metal workpiece with the cutting tool insert.
18 . The method of claim 17 , wherein side and face milling is at a cutting speed of less than about 500 m/min.
19 . The method of claim 17 , wherein side and face milling is at a cutting speed of 1 about 300 m/min to about 500 m/min.
20 . The method of claim 17 , wherein the cutting tool insert is a chamfering cutting tool insert.
21 . The method of claim 17 , wherein the metal workpiece is formed of rolled low alloyed steel.
22 . The method of claim 17 , wherein the metal workpiece is a plate and the method comprises manufacturing a tube from the milled plate.
23 . The method of claim 17 , wherein the α-Al 2 O 3 layer has a texture in the (012)-direction with a texture coefficient TC(012) larger than 1.3.
24 . The method of claim 17 , wherein the α-Al 2 O 3 layer has a texture in the (104)-direction with a texture coefficient TC(104) larger than 1.3.
25 . The method of claim 17 , wherein the α-Al 2 O 3 layer has a texture in the (110)-direction with a texture coefficient TC(110) larger than 1.3.
26 . The method of claim 17 , wherein the cemented carbide contains from about 1.4 to about 1.7 wt-% carbides of Ta and Nb.
27 . The method of claim 17 , wherein the insert has an edge radius of from about 20 to about 45 μm before coating.
28 . The method of claim 17 , wherein said edge radius is about 35 μm.
29 . The method of claim 17 , wherein said cemented carbide body comprises about 7.6 wt-% Co.
30 . The method of claim 17 , wherein an average grain size of the WC is in a range of from about 1.5 to 2.5 μm.
31 . The method of claim 17 , wherein said CW-ratio is from about 0.86 to about 0.91.
32 . The method of claim 17 , wherein the thickness of the second layer of TiC x N y O z is from about 4 to about 7 μm.
33 . The method of claim 17 , wherein the thickness of the outer layer of α-Al 2 O 3 is from about 3 to about 6 μm.
34 . The method of claim 17 , wherein a texture coefficient of the α-Al 2 O 3 layer for the set of (012), (104) or (110) crystal planes is larger than 1.5.Cited by (0)
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