Pinch Rolls
Many hot strip steel mills around the world are realizing the benefits of the Xtek Bemcalloy™ Pinch Rolls. The inherent lubrication property of the graphitic constituent in the Bemcalloy™ material, along with the natural resistance to adhesion of dissimilar metals, is the basis of the pickup resistance of the material. This resistance to pickup of the Bemcalloy™ material has proven to eliminate the rejection of coils due to poor surface quality that is attributable to adhered debris on the pinch roll working surface. The metallurgical attributes of the Bemcalloy™ material promote resistance to both adhesive and abrasive wear. This wear resistance allows for extended campaign lengths, and uniform and predictable wear throughout each campaign that the pinch roll is in service. The Xtek Bemcalloy™ Pinch Rolls also require less stock removal during regrinding, maximizing the stock available throughout the entire life cycle of the pinch roll.
Xtek Pinch Rolls are engineered for optimal performance and a value-added solution to the demanding needs of the hot steel strip coiling application. The top pinch rolls are supplied as an assembly comprising a forged alloy steel through-shaft, two forged alloy steel hubs, the Bemcalloy™ sleeve, and associated hardware. The bottom pinch rolls are supplied as an assembly comprising a forged alloy steel through-shaft, the Bemcalloy™ sleeve, and associated hardware. In both the top and bottom pinch rolls, the sleeve is a horizontally, centrifugally cast, thick-walled piece with a specific Bemcalloy™ chemistry that has been tailored to meet the specific needs of the application.
The Bemcalloy™ C-141 material is the most established of Xtek’s pinch roll material technology. This material is supplied as a horizontally, centrifugally cast, and heat-treated sleeve. The hardenability of the alloy, and the proprietary heat treatment process utilized, allows for the through-hardening of the shell, which in turn provides a uniform and predictable hardness profile throughout the life of the pinch roll.
The Bemcalloy™ C-141 material is a hypoeutectic alloy gray iron enriched with modest amounts of Chromium, Molybdenum, and Nickel. These alloys are added to the blend to exploit the material attributes of pick-up resistance and wear resistance. The alloy also contains the important alloy of Niobium, which is added to the blend to promote the formation of extremely hard niobium carbides that further enhance the wear resistance of the material. The material is supplied at 62-67 HSC (46-50 HRC). The specially balanced alloy additions of the Bemcalloy™ C-141 material also promote material attributes that aid in the integrity and stability of the pinch rolls in service. These attributes include: thermal stability, high thermal conductivity, resistance to thermal fatigue and a moderate resistance to thermal shock.
The Bemcalloy™ XA material is the latest generation of Xtek’s pinch roll material technology. This material is supplied as a dual-poured, horizontally, centrifugally cast sleeve in which the chemistry of the material varies from the outer working layer to the inner portion of the sleeve. The transition between these layers is metallurgically and mechanically sound and is substantially below the scrap diameter of the pinch roll.
The outer working layer of this blend is a white-iron based alloy enriched with modest amounts of Chromium, Molybdenum, and Nickel. The working layer alloy is specially formulated to exploit the material attributes of pick-up resistance, wear resistance and corrosion resistance. The material is supplied at 67-72 HSC (50-54 HRC). The inner portion of the shell is a ductile gray iron based alloy with physical properties that include ductility, impact strength, and tensile strength.
Contact an Xtek representative to find out more about our superior Pinch Rolls.
