Cemented carbide insert

US6333100A · kind A · utility

Assignee

• SANDVIK AB · SE

Inventors

• Lisa Palmqvist · Umeå, SE
• Mikael Lindholm · Kalmar, SE
• Anders Lenander · Tyresö, SE
• Bjorn Ljungberg · Stuvsta-Snättringe, SE
• Michael Thysell · Stockholm, SE

Key dates

• Filing date: Feb 2, 2000
• Grant date: Dec 25, 2001
• Expiry date: Feb 2, 2020

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/265
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The present invention relates to a coated cemented carbide insert for turning of steel, like low alloyed steels, carbon steels and tough hardened steels at high cutting speeds. The cemented carbide consists of WC, 2-10 wt. % Co and 4-12 wt. % of cubic carbides of metals from groups 4, 5 or 6 of the periodic table, preferably Ti, Ta and Nb. The Co-binder phase is highly alloyed with W with a CW-ratio of 0.75-0.90. The insert has a binder phase enriched and essentially cubic carbide free surface zone A of a thickness of <20 .mu.m and along a line C essentially bisecting the edge, in the direction from the edge to the centre of the insert, a binder phase content increases essentially monotonously until it reaches the bulk composition. The binder phase content at the edge is 0.65-0.75 times the binder phase content by volume of the bulk and the depth of the binder phase depletion is 100-300 .mu.m, preferably 150-250 .mu.m. The insert is coated with 3-12 .mu.m columnar TiCN-layer followed by a 2-12 .mu.m thick Al.sub.2 O.sub.3 -layer.