Method of Controlling Surface Cracks of 316ln Nuclear Power Steel Rolling

Abstract

The invention relates to a method for controlling rolling surface cracks of 316LN nuclear power steel, which includes billet coating control, billet heating control and billet rolling control. Heating stage 1, heating stage 2 and soaking stage, heating temperature of preheating stage ≤ 1100°C, heating time of preheating stage ≥ 1.5h, heating temperature of stage 1, heating stage 2 and soaking stage 1250-1280°C, heating stage 1 The heating time is 1~1.5h, the heating time of the second stage of heating is 1.5~2h, the heating time of the soaking section is 2~2.5h, and the total time in the furnace is controlled to be ≥6h; the rolling control of the billet includes the rolling of the billet by the two-fire rolling process , the first hot rolling rolls the steel billet with the initial thickness to the intermediate billet with the intermediate thickness, and the second hot rolling rolls the intermediate billet to the finished product with the finished thickness. This method can effectively improve the problem of cracks on the rolling surface of 316LN nuclear power steel.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and relates to a method for controlling cracks on the rolling surface of 316LN nuclear power steel. Background technique [0002] 316LN nuclear power steel is a type of steel used in nuclear fusion high-energy power generation equipment. It is produced by continuous casting and rolling. This type of steel requires a magnetic permeability of <1.05 and a complete austenite structure. 316LN nuclear power steel is characterized by high Ni and N content, such as Ni content above 10%, C+N ≥ 0.15%. The increase of Ni content reduces the Cr / Ni equivalent, the rolling thermoplasticity becomes worse and the single-phase structure is easy to form cracks; the increase of N content increases the strength to a certain extent, but the rolling surface is easy to crack. Therefore, due to the stringent requirements for the composition of 316LN nuclear power steel, there are cracks on the surf...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the defects and deficiencies of cracks on the rolling surface of 316LN nuclear power steel in the prior art, the present invention provides a method for controlling the cracks on the rolling surface of 316LN nuclear power steel, through heating control and rolling control in the production process of 316LN nuclear power steel , effectively improved the problem of cracks on the rolling surface of 316LN nuclear power steel, improved the pass rate of finished products, and met the special needs and use of materials for key projects