High-strength alloy nodular cast iron coarse roller and production process thereof

Abstract

The invention discloses a high-strength alloy nodular cast iron coarse roller and a production process thereof. The high-strength alloy nodular cast iron coarse roller comprises the following chemicalcomponents of, in percentage by mass, 3.0-3.5 of C, 1.2-1.8 of Si, 0.7-1.0 of Mn, less than or equal to 0.03 of P, less than or equal to 0.015 of S, 1.2-2.2 of Ni, 0.3-0.8 of Mo, 0.1-0.5 of V, 0.2-1.0 of Cr, 0.045-0.075 of Mg, 0.01-0.016 of Re, and the balance Fe and unavoidable impurities. According to the coarse roller and the production process thereof, the forming quantities of different types of carbides in a material are increased through the reasonable addition of alloy elements such as Cr, Mo and V, so that the wear resistance of the material is improved; proper quantities of the elements are dissolved in a substrate, so that the strength of the material is improved; and the combined action of Mg and Re reduces the cutting action, on the substrate, by graphite, so that the strength and toughness of the material are further improved.

Description

technical field [0001] The invention relates to the field of metallurgy, in particular to a high-strength alloy ductile iron rough roll and a production process thereof. Background technique [0002] At present, rolls made of forged steel or partially cast steel are usually used on the section steel blanking stand, the big bar roughing stand and the strip two-roller roughing stand at home and abroad due to the large rolling force. These rolls have high strength but poor wear resistance. As a result, frequent roll changes in the rolling process affect the work efficiency, and at the same time, the surface quality of the rolled material is poor due to poor wear resistance. Chinese patent CN106636879A discloses a nodular cast iron roll body and its preparation method, which solves the problems of casting defects such as shrinkage porosity, shrinkage cavity, slag inclusion, sand inclusion and cracks in the large-size nodular cast iron roll body in the prior art , but its low st...

AI Technical Summary

Problems solved by technology

[0002] At present, rolls made of forged steel or partially cast steel are usually used on the section steel blanking stand, the big bar roughing stand and the strip two-roller roughing stand at home and abroad due to the large rolling force. These rolls have high strength but poor wear resistance. Frequent roll changes during the rolling process affect operational efficiency, and the surface quality of the rolled material is poor due to poor wear resistance

Chinese patent CN106636879A discloses a nodular cast iron roll body and its preparation method, which solves the problems of casting defects such as shrinkage porosity, shrinkage cavity, slag inclusion, sand inclusion and cracks in the large-size nodular cast iron roll body in the prior art , but its low strength and poor wear resistance can not meet the needs of rough rolling; Chinese patent CN101654734A discloses a method for manufacturing alloy ductile iron rolls for universal rolling mills. The method includes smelting, molten iron spheroidization and inoculation treatment, casting rolls, Cooling and unpacking, pre-cutting, this method adopts heat treatment process after pre-cutting, so that the roll undergoes high-temperature austenitization and homogenization, and then through rapid cooling, the groove bottom and side matrix structure of the slotted roll is obtained. refinement, to meet the wear resistance of the groove bottom and side of the roll, but its complicated manufacturing process can basically only meet the rough rolling stand with low rolling force, and the total manufacturing cost is also high; Chinese patent CN102268588B discloses a steel pipe reducing Sizing machine or sizing machine nodular cast iron roll and its preparation method adopts a nickel-free scheme and reduces other alloy content in the composition of the nodular cast iron roll. The heat treatment adopts a two-step method for austempering, and obtains a more conventional heat-treated nodular cast iron roll. Good mechanical properties, so that the strength and toughness are greatly increased, but this roll manufacturing method can only meet the finished product stand with low rolling force requirements and cannot be well suited for rough rolling stands with high rolling force requirements. Nickel-free and The roll manufactured by the scheme with low alloy content has low strength and poor wear resistance, resulting in low excess steel and prone to roll breakage accidents