轧辊的磨损-精选课件(设计).pptVIP

* Roll Wear in HSM WEAR in HSM CLASSIFICATION of WEAR ABRASIVE WEAR ADHESIVE WEAR FATIGUE WEAR CHEMICAL WEAR IC RD DEPT LOSS of TOOL MATERIAL during DEFORMATION SKETCHS of MECHANISMS WEAR in HSM ABRASIVE WEAR IC RD DEPT REMOVAL of MATERIAL by HARD ASPERITY (2-body wear) by PARTILES LOCATED between 2 SURFACES (3-body wear) MECHANISM AFFECTS by ROLL HARDNESS OXIDE SCALE Carbon (%) 1 2 3 WEAR in HSM ADHESIVE WEAR IC RD DEPT JUNCTIONS (MICRO WELDING) GENERATED by PLASTIC DEFORMATION of ASPERITY SEPARATION or BREAKING MAY LEAD LOSS of MATERIAL MECHANISM AFFECTS by CONTACT COMPATIBILITY of SURFACES WEAR in HSM FATIGUE WEAR IC RD DEPT CYCLICAL LOADING MECHANICAL microcracks delamination (flat sheet-like particle detachment) THERMAL cracks firecrack pattern PITTING, SPALLING… WEAR in HSM CHEMICAL WEAR IC RD DEPT LOSS of MATERIAL due to TRIBOCHEMICAL REACTIONS ROLL STRIP LUBRIFICANT ENVIRONMENT WEAR in HSM ROLL WEAR IC RD DEPT COMPLEX PHENOMENON SEVERAL MECHANISM ACTING at the SAME TIME… CORROSION THERMAL FATIGUE ABRASION MECHANICAL FATIGUE WEAR in HSM ROLL WEAR IC RD DEPT ROLLING PARAMETERS WEAR in HSM FACTORS INFLUENCING ROLL WEAR IC RD DEPT FRICTION HOT-ROLLED STEEL LOADS STRESSES ROLL MATERIAL COOLING LUBRICATION WEAR in HSM HOT-ROLLED STEEL IC RD DEPT CHEMISTRY MECHANICAL PROPERTIES HAVE a STRONG EFFECT on WEAR DEFORMATION RESISTANCE WEAR TEMPERATURE CONTROLS GROWTH TYPE of OXIDE SCALE WEAR in HSM HOT-ROLLED STEEL TERTIARY SCALE in FINISHING GROUP IC RD DEPT CONTROLLING STRIP TEMEPERATURE below 950°C IMPROVES ROLL PERFORMANCE FeO ACTS AS A LUBRIFICANT THERMAL FATIGUE OXIDE FILM STABILITY on ROLL SURFACE WEAR in HSM IC RD DEPT but another theory exists also LOOKED in LABORATORY TESTS WEAR SHOWS a MAXIMUM at 900-950°C Above 950°C SCALE SHEARS INTERNALLY: WEAR FRICTION DECREASE Below 950°C WEAR INCREASE with TEMPERATURE: ROLL SOFTENING HARDER SCALE HOT-ROLLED STEEL TERTIARY SCAL