Smelting process for improving low-temperature impact energy of 32CrNi3MoVE steel

Abstract

The invention relates to a smelting process for improving the low-temperature impact energy of 32CrNi3MoVE steel. The smelting process comprises the following steps: (1) carefully selecting ingredients, and controlling the content of harmful elements; (2) smelting in an electric furnace, controlling carbon, phosphorus and temperature to meet process requirements, and adding ferrosilicon, ferromanganese, an aluminum block deoxidizing agent and a lime slagging material along with steel flow during tapping; (3) carrying out argon blowing refining, heating, deoxidation, alloy component adjustment, vacuum degassing, argon blowing and calcium feeding line reinforced deoxidation, and carrying out tapping when the components are qualified; (4) carrying out die casting to obtain an electrode blank; and (5) carrying out electroslag on the electrode blank to form an electroslag ingot by adopting ternary slag production and argon protection, and controlling [Al] to be less than or equal to 0.025%. The transverse AKV (minus 40 DEG C) of the 32CrNi3MoVE steel produced by the smelting method is greater than or equal to 20J.

Description

technical field [0001] The invention belongs to the technical field of steelmaking technology, and relates to a low-aluminum steel smelting technology, in particular to a smelting technology for improving low-temperature impact energy of 32CrNi3MoVE steel. Background technique [0002] 32CrNi3MoVE steel is used to make thick-walled pipes. This type of steel has high hardenability. After quenching and tempering heat treatment, it can obtain good strength and plastic fit, and has high resistance to brittle fracture. The material requires AKV (-40°C) impact energy ≥ 20J, and the impact energy stability is poor in actual production, and there are cases where the impact energy of the ingot tail is lower than 20J. [0003] Before 2020, the slag system used for electroslag was binary slag, and the ratio of the slag system was CaF2:Al2O3=70:30. According to the statistics of production data, the riser and ingot tail end [Al] were all ≤0.025%, AKV (-40℃ ) impact energy ≥ 20J, but th...

AI Technical Summary

Problems solved by technology

The material requires AKV (-40°C) impact energy ≥ 20J, the impact energy stability is poor in actual production, and there are cases where the impact energy of the ingot tail is lower than 20J

[0003]Before 2020, the slag system used for electroslag was binary slag, and the slag system ratio was CaF2:Al2O3=70:30. According to the statistics of production data, the riser, ingot The tail end [Al] is ≤0.025%, and the impact energy of AKV (-40°C) is ≥20J, but this slag system is easy to cause sulfide inclusions exceeding the standard; the slag used in electroslag is self-mixed ternary slag (CaF2:Al2O3 : CaO=65:20:15), the lime part is replaced by pre-melted slag; the slag is at the riser end [Al] ≤ 0.025%, the impact energy of AKV (-40 ℃) is ≥ 20J, and the ingot tail end [Al] ] Fluctuates between 0.012 and 0.050%