A Centrifugal Composite Casting Method for High Speed ​​Steel Rolls with Low Interface Failure

Abstract

The invention discloses a centrifugal composite casting method for a high-speed steel roll with low interfacial failure. The centrifugal composite casting method comprises the following steps of firstly, casting outer-layer high-speed molten steel with the temperature of 1,400-1,450DEG C in a high-speed rotating roll casting mold on a centrifugal machine, and after the casting is finished, adding casting powder in the casting mold; secondly, separately determining the casting time and the casting temperature of ductile cast molten iron according to chemical components in the high-speed molten steel and chemical components in the ductile cast molten iron and controlling the casting thickness of a transitional layer; thirdly, when the interface temperature of the inner surface of the transitional layer is cooled to be 1,050-1,150DEG C, lifting out a roll casting mold for closing and statically casting high-temperature ductile cast molten iron with the temperature of 1,330-1,370DEG C at the core part; fourthly, performing insulated cooling to room temperature, and performing opening, rough machining, quenching, tempering treatment and finish machining to obtain the high-speed steel roll with the low interfacial failure. The roll surface cast by the centrifugal composite casting method disclosed by the invention is good in metallurgical structure and high in bonding strength; an outer layer is not easy to strip off.

Description

technical field [0001] The invention relates to the technical field of roll casting, in particular to a centrifugal composite casting method for high-speed steel rolls with low interface failure. The rolls cast by the casting method have the characteristics of good interface metallurgical bonding and high bonding strength. When the material is rolled, it has a low interface failure ability and the outer layer is not easy to peel off. Background technique [0002] At present, the main type of failure of centrifugal composite casting rolls during use is that the outer layer peels off from the bonding layer. The main reason is that the metallurgical bonding of the bonding layer is poor and the bonding strength is low. It is easy to occur due to the rolling force during the rolling process Combined with layer high cycle fatigue, with the prolongation of the rolling process, fatigue cracks expand and propagate, and when the cracks expand to the critical spalling value, they canno...

AI Technical Summary

Problems solved by technology

[0002] At present, the main type of failure of centrifugal composite casting rolls during use is that the outer layer peels off from the bonding layer. The main reason is that the metallurgical bonding of the bonding layer is poor and the bonding strength is low. It is easy to occur due to the rolling force during the rolling process Combined with layer high cycle fatigue, with the extension of the rolling process, fatigue cracks expand and propagate, and when the cracks expand to the critical spalling value, they cannot resist the rolling force and cause large-area spalling of the outer layer

The metallurgical bonding of the bonding layer is poor and the bonding strength is low, which is caused by two reasons: 1. The inner and outer layers are too thin to cause weak bonding, resulting in low bonding strength of the bonding layer; 2. The inner and outer layers are too thick to cause the outer layer to be high Excessive infiltration of alloy components into the inner ductile iron causes a decrease in the strength index of the transition inner ductile iron, resulting in a decrease in the bonding strength of the bonding layer

For example, Chinese patent CN102990031.A discloses a centrifugal compound casting method for high-boron high-speed steel rolls, which is characterized in that when the inner surface temperature of the outer layer high-boron high-speed steel roll body is 1300-1350 ° C, continue to rotate at a speed of 700-750 rpm On a centrifuge with a temperature of 1450-1470°C, pour high-temperature nodular cast iron molten iron in the transition layer, and control the pouring thickness of the transition layer to 15-20mm. The temperature parameters of cast iron molten iron are used to realize centrifugal casting molding, which will easily cause the inner and outer layers of mutual melting layer to be too thick, resulting in excessive high-alloy components in the outer layer infiltrating into the inner layer of nodular iron, causing a decrease in the strength index of the transition inner layer of nodular iron, resulting in the bonding of the bonding layer Low strength; for example, Chinese patent CN102274856.A discloses a centrifugal composite high-speed steel roll and its pouring method, which is characterized in centrifugal casting, pouring temperature 1420-1480°C, casting the outer layer of high-speed steel first, centrifugal weight multiple 100-120G, The casting thickness is 90-110mm. When the cast layer is cooled to 1225-1245°C, the intermediate transition layer is centrifugally cast. The casting thickness is 40-60mm, and the centrifugal weight multiple is 100-120G. When the cast layer is cooled to 1220-1240°C, stop. The disadvantage is that when the chemical composition of the outer layer is centrifugally cast, it is difficult to accurately control the intermelted thickness of the outer layer and the transition layer by using a narrow casting layer temperature parameter, and it is difficult to guarantee the metallurgical bonding quality and bonding strength of the bonding layer.

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