CN104087808A - A preparing method of a nickel- and chromium- containing automobile wheel hub bearing unit - Google Patents

Abstract

A preparing method of a nickel- and chromium- containing automobile wheel hub bearing unit is disclosed. The preparing method includes steps of: 1) subjecting an iron-containing ore material to dehydration pretreatment, and sintering to obtain sinter; and 2) subjecting the sinter to smelting in a blast furnace to obtain molten iron, putting a compound modifier having a weight accounting for 2.0-3.0% of the weight of the molten iron at the bottom of a pouring ladle, and subjecting the molten iron to compound modification processing by adoption of an in-ladle pour-over method at 1300-1400 DEG C, wherein the iron-containing ore material comprises 30-40% by weight of limonite and 35-45% by weight of haematite, with the balance being laterite-nickel ore, and the compound modifier comprises 50-55% by weight of FeNB50, 20-25% by weight of FeSiRe21, 20-25% by weight of FeBa5Si60 and 5-10% by weight of yttrium-based rare earth. The preparing method overcomes the defect that conventional low-grade laterite-nickel ore is not comprehensively utilized. The prepared alloy steel has the advantages of high strength, corrosion resistance, weatherability, and the like, and has good economic benefits.

Description

A kind of preparation method of Ni and Cr contained automobile hub bearing

 

Technical field

The present invention relates to steel alloy field of smelting, be specifically related to a kind of preparation method of Ni and Cr contained automobile hub bearing.

 

Background technology

At present, China's iron ore deposit gradually reduces, and iron and steel production capacity is significantly expanded, and the most of dependence of the iron ore deposit import of Iron and Steel Production is with high costs.Along with the quickening of urbanization process, the security of buildings more and more comes into one's own.Domestic existing building trade adopts the hot rolled ribbed steel bar of HRB335, HRB400 model more, but the intensity of these model reinforcing bars, Anti-seismic standard are well below the external even higher reinforcing bar of HRB500 generally using.The domestic research about high strength cast iron mainly concentrates in micro-interpolation, as Chinese patent CN101717898A discloses a kind of HRB500E high-strength anti-seismic steel bar that contains boron nitrogen microalloy; Chinese patent CN101696484A discloses a kind of HRB400 hot rolled ribbed steel bar that contains vanadium, chromium.But in these technology, need to add the content that expensive alloy is adjusted trace element in molten steel, and iron ore price is soaring year by year, has caused the manufacturing cost of whole reinforcing bar high.

In red soil nickel ore, contain the valuable metals such as nickel, chromium, wherein also contain a large amount of iron.At home, in recent years adopt pyrometallurgical smelting laterite nickel ore and producing ferronickel, as the source of iron of making steel, start to come into one's own.A large amount of low-grade and super low-grade nickel minerals in red soil nickel ore, as nickeliferous below 1.5%, iron content 30%-50%, the low-grade laterite nickel ore of nickeliferous≤1%, iron content 45%-50% particularly, wherein contained various elements also can not get comprehensive utilization at present.

 

Summary of the invention

The preparation method who the object of this invention is to provide a kind of nickel-chrome alloy steel, overcomes the defect that existing low-grade laterite nickel ore can not get comprehensive utilization, and it possesses high strength, the performance such as anticorrosive, weather-proof steel alloy, has good economic benefit.

Technical scheme of the present invention is as follows:

A preparation method for Ni and Cr contained automobile hub bearing, includes following operation steps,

1), will be agglomerate containing dewater pre-treatment sintering of iron ore material, described containing iron ore material by weight percentage by 30～40% limonite, 35～45% rhombohedral iron ore, surplus is that red soil nickel ore forms;

2), agglomerate is obtained to molten iron through blast-furnace smelting, 2.0～3.0% compound modifiers of weight of molten iron are placed in to casting ladle bottom, with pouring method in bag, molten iron is carried out to composite inoculating processing, temperature of reaction is 1300～1400 ℃, and the chemical component weight per-cent of described compound modifier is: FeNB50 50～55%, FeSiRe21 20～25%, FeBa5Si60 20～25%, Yttrium base rare earth 5～10%;

3), described molten iron is carried out to refining by converter or electric furnace, and regulate in molten steel chemical component weight percentage ratio to form to meet as follows: C:0.23～0.34%; Si:0.5～0.7%; Mo:0.03～0.06%, Mn:0.7～1.3%; Ni:0.65～1.4%; Sr:0.25～0.48%; V:0.03～0.25%; Pb :≤0.02%; S :≤0.02%; Surplus is Fe;

4), the molten steel after refining is carried out to casting and become hub-bearing unit foundry goods;

5), thermal treatment, in described heat treatment step, the hub-bearing unit blank that casting is formed carries out solid solution, timeliness and hardening to be processed, wherein, solid solubility temperature is set in 500 ℃ ± 5 ℃, solution time 6-7 hour, and aging temp is set in 120 ℃ ± 5 ℃, solution time 4.5-5.5 hour, hardening groove Temperature Setting is at 60～70 ℃.

Preparation method of the present invention, without the special alloy that adds nickel or chromium in preparation process, has simplified production technique.And the increase due to nickel, chromium element in steel alloy, can also reduce the addition of manganese element, and has obviously improved the performance of steel, make it possess high strength, the performance such as anticorrosive, weather-proof, there is good economic benefit, social benefit and application prospect.

Steel alloy prepared by the inventive method possesses performance index: yield strength YS is 780-800MPa, tensile strength TS is 1100-1220MPa, and strong flexor ratio TS/YS is 1.2-1.4, unit elongation 18-21%, uniform elongation 7.8～10.0%, weather resistance is better than CortenA.

 

Embodiment

A preparation method for Ni and Cr contained automobile hub bearing, includes following operation steps,

1), will be agglomerate containing dewater pre-treatment sintering of iron ore material, described containing iron ore material by weight percentage by 30～40% limonite, 35～45% rhombohedral iron ore, surplus is that red soil nickel ore forms;

2), agglomerate is obtained to molten iron through blast-furnace smelting, 2.0～3.0% compound modifiers of weight of molten iron are placed in to casting ladle bottom, with pouring method in bag, molten iron is carried out to composite inoculating processing, temperature of reaction is 1300～1400 ℃, and the chemical component weight per-cent of described compound modifier is: FeNB50 50～55%, FeSiRe21 20～25%, FeBa5Si60 20～25%, Yttrium base rare earth 5～10%;

3), described molten iron is carried out to refining by converter or electric furnace, and regulate in molten steel chemical component weight percentage ratio to form to meet as follows: C:0.23～0.34%; Si:0.5～0.7%; Mo:0.03～0.06%, Mn:0.7～1.3%; Ni:0.65～1.4%; Sr:0.25～0.48%; V:0.03～0.25%; Pb :≤0.02%; S :≤0.02%; Surplus is Fe;

4), the molten steel after refining is carried out to casting and become hub-bearing unit foundry goods;

5), thermal treatment, in described heat treatment step, the hub-bearing unit blank that casting is formed carries out solid solution, timeliness and hardening to be processed, wherein, solid solubility temperature is set in 500 ℃ ± 5 ℃, solution time 6-7 hour, and aging temp is set in 120 ℃ ± 5 ℃, solution time 4.5-5.5 hour, hardening groove Temperature Setting is at 60～70 ℃.

Claims (1)

1. a preparation method for Ni and Cr contained automobile hub bearing, is characterized in that, includes following operation steps,

1), will be agglomerate containing dewater pre-treatment sintering of iron ore material, described containing iron ore material by weight percentage by 30～40% limonite, 35～45% rhombohedral iron ore, surplus is that red soil nickel ore forms;

2), agglomerate is obtained to molten iron through blast-furnace smelting, 2.0～3.0% compound modifiers of weight of molten iron are placed in to casting ladle bottom, with pouring method in bag, molten iron is carried out to composite inoculating processing, temperature of reaction is 1300～1400 ℃, and the chemical component weight per-cent of described compound modifier is: FeNB50 50～55%, FeSiRe21 20～25%, FeBa5Si60 20～25%, Yttrium base rare earth 5～10%;

3), described molten iron is carried out to refining by converter or electric furnace, and regulate in molten steel chemical component weight percentage ratio to form to meet as follows: C:0.23～0.34%; Si:0.5～0.7%; Mo:0.03～0.06%, Mn:0.7～1.3%; Ni:0.65～1.4%; Sr:0.25～0.48%; V:0.03～0.25%; Pb :≤0.02%; S :≤0.02%; Surplus is Fe;

4), the molten steel after refining is carried out to casting and become hub-bearing unit foundry goods;

5), thermal treatment, in described heat treatment step, the hub-bearing unit blank that casting is formed carries out solid solution, timeliness and hardening to be processed, wherein, solid solubility temperature is set in 500 ℃ ± 5 ℃, solution time 6-7 hour, and aging temp is set in 120 ℃ ± 5 ℃, solution time 4.5-5.5 hour, hardening groove Temperature Setting is at 60～70 ℃.