Preparation method of high-hardness and high-strength expanding pyramid of mechanical expanding mill

A high-strength, high-hardness technology, applied in the direction of improving process efficiency, etc., to achieve the effect of excellent mechanical properties

Active Publication Date: 2015-03-25
HUNAN UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, there is no report on the heat treatment process of similar expanding cones

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] The cone of this embodiment is a large-scale austenitic-bainite ductile iron expanding cone.

[0027] (1) Smelting, spheroidizing, incubating, pouring:

[0028] ① Ingredients: Q10 newborn iron 55%, returned furnace iron 10%, steel scrap 30%, 65# ferromanganese 0.60%; 55% ferromolybdenum 0.60%, 99% copper 0.70%, nodulizer 1.5%, 75# ferrosilicon inoculant 2.40%, long-acting rare earth inoculant 0.2%.

[0029] ②Smelting: Pig iron, returned iron, and scrap steel are first put into the furnace for melting. When the temperature of molten iron reaches 1450°C, ferromanganese is added. After ferromanganese is put in for 3 minutes, perlite is added to make slag twice. The second time, remove the slag, control the temperature of the molten iron to be 1400°C, and the molten iron smelting time is no more than 2 hours.

[0030] ③ Spheroidization + inoculation: Nodulizer + 2.40% 75# ferrosilicon inoculant is placed on the bottom side of the ladle, and covered with a thin steel plate...

Embodiment 2

[0040] The cone of this embodiment is a medium-sized austenitic-bainite ductile iron expanding cone.

[0041] (1) Smelting, spheroidizing, incubating, pouring:

[0042] ① Ingredients: Q10 virgin iron 50%, returned iron 15%, scrap steel 29.4%, 65# ferromanganese 0.50%; 55% ferromolybdenum 0.50%, 99% copper 0.75%, nodulizer 1.45%, 75# ferrosilicon inoculant 2.30%, long-acting rare earth inoculant 0.1%.

[0043] ②Smelting: pig iron, returned iron, and scrap steel are first put into the furnace for melting, and when the temperature of molten iron reaches 1430°C, ferromanganese is added. After ferromanganese is put in for 2.5 minutes, perlite is added to make slag twice. The second time, remove the slag, control the temperature of the molten iron to be 1410°C, and the molten iron smelting time is no more than 2 hours.

[0044] ③ Spheroidization + inoculation: Nodulizer + 2.30% 75# ferrosilicon inoculant is placed on the bottom side of the ladle and covered with a thin steel plate t...

Embodiment 3

[0054] The cone of this embodiment is a small-sized austenitic-bainite ductile iron expanding cone.

[0055] (1) Smelting, spheroidizing, incubating, pouring:

[0056] ① Ingredients: Q10 newborn iron 54.9%, returned furnace iron 14.95%, scrap steel 25%, 65# ferromanganese 0.55%; 55% ferromolybdenum 0.55%, 99% copper 0.60%, nodulizer 1.20%, 75# ferrosilicon inoculant 2.10%, long-acting rare earth inoculant 0.15%.

[0057] ②Smelting: pig iron, returned iron, and scrap steel are first put into the furnace for melting, when the temperature of molten iron reaches 1420°C, ferromanganese is added, and after ferromanganese is put in for 2 minutes, perlite is added to make slag twice, the slag is cleaned, ferromolybdenum is put in, and perlite is added to make slag 1 The second time, remove the slag, control the temperature of the molten iron to be 1420°C to discharge the molten iron, and the molten iron smelting time is no more than 2 hours.

[0058] ③ Spheroidization + inoculation:...

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Abstract

The invention discloses a preparation method of a high-hardness and high-strength expanding pyramid of a mechanical expanding mill. The preparation steps are as follows: (1) smelting, spheroidizing, inoculating and casting; (2) annealing; (3) plugging holes with refractory clay and asbestos, blocking grooves, sealing center holes so that the preparation works are completed; (4) charging the expanding pyramid of which the large end downwards faces into a tooling of which the bottom is a plane, placing the tooling inside a well-type heating furnace and drying the refractory clay so as to complete the charging operation; (5) by controlling the temperature-raising speed and the temperature-raising temperature, heating; (6) by controlling the temperature-raising speed, the temperature-raising temperature and the temperature-raising time, austenitizing; (7) by controlling the time and temperature, carrying out three-stage quenching; and (8) by controlling the time and temperature, tempering. The high-hardness and high-strength austenitic-bainitic nodular cast iron expanding pyramid subjected to above treatment steps has no defects such as quenching cracks, high quenching depth, good compressive strength, impact toughness and hardness, can meet the needs of machining and cannot be deformed after machining. The expanding pyramid is suitable for preparing steel tubes having steel grade of X60-X80 and wall thickness of 10-18 mm.

Description

technical field [0001] The invention relates to a method for preparing a diameter-expanding cone used in a mechanical diameter-expanding machine, in particular to a preparation method for a complex-shaped, high-hardness and high-strength austenite-bainite ductile iron diameter-expanding cone. Background technique [0002] Expanding dies for mechanical expanding machines-expanding cones are a very critical mold for forming steel pipes. At present, my country mainly buys them from SMS MEER in Germany and FONTIJINE GROTNES in the Netherlands. It is required to be able to expand pipes stably. branch. [0003] During the expansion process, in order to cause the expansion deformation of the steel pipe, the expansion cone needs to bear huge pressure and friction force. In order to ensure the performance of the expansion cone, the cast NiCrMoCu anti-friction cast iron and carburized 38CrMoAlA alloy steel are currently used. preparation. Due to the complex shape of the expanding con...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C33/04C21D1/26C21D1/00C21D1/18
CPCY02P10/20
Inventor 王振生彭真杨双双宋力
Owner HUNAN UNIV OF SCI & TECH
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