A kind of preparation method of nickel-chromium alloy steel

Abstract

The invention discloses a preparation method for nickel-chrome-containing alloy steel. The preparation method comprises the following operation steps: 1) subjecting iron-containing mineral aggregate to dehydration pretreatment and sintering so as to obtain agglomerate, wherein the iron-containing mineral aggregate comprises, by weight, 20 to 40% of limonite and 30 to 50% of hematite, with the balance being Laterite-nickel ore; and 2) subjecting the agglomerate to blast furnace smelting so as to obtain molten iron, placing a composite modifier accounting for 1.0 to 2.0% of the weight of the molten iron at the bottom of a casting ladle and carrying out composite modification on the molten iron through an in-ladle nodularizing process with reaction temperature being 1400 to 1500 DEG C, wherein the composite modifier comprises the following chemical components by weight: 50 to 55% of FeNB50, 20 to 25% of FeSiRe21, 20 to 25% of FeBa5Si60 and 5 to 10% of yttrium-based rare earth. The preparation method provided by the invention overcomes the defect that conventional low-grade Laterite-nickel ore is not comprehensively used; and the prepared alloy steel has the advantages of high strength, corrosion resistance, weatherability and good economic benefits.

Description

technical field [0001] The invention relates to the field of alloy steel smelting, in particular to medium and low alloy steel containing nickel and chromium and a preparation method thereof. Background technique [0002] At present, my country's iron ore resources are gradually decreasing, and steel production capacity has been greatly expanded. Most of the iron ore resources for steel production are imported, and the cost is high. With the acceleration of the urbanization process, the safety of buildings has been paid more and more attention. The existing domestic construction industry mostly uses HRB335 and HRB400 hot-rolled ribbed steel bars, but the strength and seismic standards of these types of steel bars are far lower than the HRB500 or even higher steel bars commonly used abroad. Domestic research on high-strength steel bars mainly focuses on the addition of trace elements. For example, Chinese patent CN101717898A discloses a HRB500E high-strength seismic steel ba...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a preparation method of nickel-chromium alloy steel, which overcomes the defect that the existing low-grade laterite nickel ore cannot be comprehensively utilized. The alloy steel has high strength, corrosion resistance, weather resistance and other properties, and has good economic benefits