Method for producing 30CrMo hot rolled steel plate

Abstract

The invention discloses a method for producing a 30CrMo hot rolled steel plate, which mainly comprises the steps of smelting, refining, thin slab casting, soaking, high pressure water descaling, hot continuous rolling, cooling and reeling based on the process of thin slab casting and rolling. The withdrawing speed of continuous casting is S withdrawing (3.5m / min < / = S withdrawing < / = 5.5m / min), the charging temperature of casting blanks is T charging (900 DEG C < / = T charging < / = 1050 DEG C), the final rolling temperature is T final (830 DEG C < / = T final < / = 930 DEG C), the reeling temperature is T reeling ( 520 DEG C < / = T reeling < / = 620 DEG C), and the depth of a single-surface decarburized layer is 0.2 to 1.2 percent of the thickness of the steel plate. The chemical constitutes of molten steel after being alloyed in a refining process comprise 0.26-0.34 wt.% of C, 0.17-0.37 wt.% of Si, 0.40-0.70 wt.% of Mn, less than or equal to 0.035 wt.% of P, less than or equal to 0.035 wt.% of S, 0.80-1.10 wt.% of Cr, 0.15-0.25 wt.% of Mo and the balance of Fe and inevitable impurities. The 30CrMo hot rolled steel plate produced in the method has the characteristics of uniform structure property, high thermal stability and high strength, and the quality of the 30CrMo hot-rolled steel plate is obviously improved.

Description

technical field [0001] The invention relates to the technical field of alloy structural steel production, in particular to a method for producing 30CrMo hot-rolled steel plates. Background technique [0002] 30CrMo alloy structural steel has high strength and toughness, good hardenability, and has good comprehensive mechanical properties after quenching and tempering at low temperature and after quenching and high temperature tempering. After quenching and tempering, the steel has higher strength below 550°C. Steel has good low-temperature toughness, no temper brittleness, good weldability and machinability, and is widely used in medium-sized machinery manufacturing, chemical industry, boiler manufacturing, and tool and mold industries. The appropriate combination of Cr and Mo elements in 30CrMo makes the steel have good comprehensive mechanical properties at room temperature and high temperature, and obtains dense structure and high strength without significantly reducing ...

AI Technical Summary

Problems solved by technology

[0003] Usually 30CrMo hot-rolled steel plate is produced by the traditional process, and there are the following main problems: due to the high carbon content of 30CrMo, complex alloy composition, low casting speed of thick slab continuous caster, and slow solidification of molten steel, it is easy to cause slab composition segregation and loosening, It leads to uneven microstructure and properties of the final product; using a walking heating furnace to heat the slab, the heating time is long, the temperature is high, and the surface of the slab is seriously decarburized, which directly affects the surface hardness, wear resistance and thermal stability of the product; 30CrMo The solidification temperature is low, and the continuous casting speed of the traditional process is slow, resulting in low temperature of the slab, entering the low-temperature plastic zone, and cracks on the surface and edge of the slab, directly affecting product quality

However, the application requires many types of alloys, and the quantity is large, and the production cost is high

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