- Flank abrasive wear (most common)
Long-term friction with high-temperature oxide scales and hot steel causes uniform abrasion on the clearance face. The cutting edge becomes blunt, leading to poor scarfing surface quality and increased cutting load. This is the normal service life termination form for standard working conditions.
- Crater wear on the rake face
Intense high-temperature extrusion and chemical diffusion between chip and insert top surface form sunken craters near the cutting edge. Severe crater wear weakens the edge strength and easily triggers subsequent edge breakage.
- Thermal fatigue cracking (heat check cracks)
Repeated drastic temperature alternation between red-hot steel contact and air cooling produces tiny network thermal cracks on the edge. These cracks expand continuously during operation and finally cause edge peeling or large-area chipping.
- Local edge chipping and micro breakage
Intermittent impact from uneven billet surfaces, hard inclusions or sudden overload leads to small fragments falling off the cutting edge. It mostly occurs on the tip and main cutting edge, directly making the insert invalid.
- Built-up edge peeling tearing the edge
Hot steel material sticks firmly onto the insert edge to form built-up edge. When the adhered metal falls off forcibly, it often tears small carbide particles away from the cutting edge, accelerating premature failure.
- Plastic deformation collapse under high heat and pressure
Under ultra-high temperature and heavy cutting force, the local carbide material loses hardness and yields plastic deformation. The edge collapses or sinks inward, losing the original cutting geometry.
