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Steel for tandem tube mill hollow mandrel and preparation technology thereof

A hollow mandrel rod and preparation process technology, applied in metal rolling, manufacturing tools, metal rolling and other directions, can solve the problems of long working hours and high processing costs

Inactive Publication Date: 2012-01-25
SHANGHAI UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the method of machining the inner hole of the hollow mandrel by machining is relatively expensive and takes a long time

Method used

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  • Steel for tandem tube mill hollow mandrel and preparation technology thereof
  • Steel for tandem tube mill hollow mandrel and preparation technology thereof

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Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0025] 1. present embodiment has produced a kind of steel, and its main component is as follows:

[0026] C 0.27%, Si 0.65%,

[0027] Mn 0.65%, Cr 3.36%,

[0028] Mo 0.5%, V 0.42%,

[0029] Fe balance

[0030] 2. Preparation process and heat treatment process:

[0031] (a) Smelting: After the alloy is designed according to the above composition, it is smelted according to the traditional method. The batch materials in the above formula are placed in an electric furnace and smelted at a temperature above 1500°C; then refining and vacuum degassing are carried out. Finally, pour into ingots at about 1500-1560°C;

[0032] (b) Forging process: steel ingot is heated to 1150-1250°C for rough forging, the final forging temperature is ≤850°C; stress relief annealing is carried out after forging, the annealing temperature is 660-670°C;

[0033] (c) Rolling: The forged material is heated in a ring furnace at a temperature of 1150°C-1200°C, then pierced, rolled and formed by a PQF ro...

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Abstract

The invention relates to a steel for a tandem tube mill hollow mandrel and a preparation technology thereof. The steel comprises the following components in percentage by weight: 0.15-0.35% of C, 0.45-0.85% of Si, 0.45-0.85% of Mn, 2.5-5.0% of Cr, 0.30-0.70% of Mo, 0.20-0.60% of V and the balance of Fe. The preparation technology for the material comprises the following steps of: smelting in an electric furnace, remelting electroslag, annealing, forging and annealing to cause the tandem tube mill hollow mandrel to have good machinability; and carrying out heat treatment (quenching to high-temperature tempering). Under the recommended heat treatment process condition, the hardness is 327-344HB (Brinell hardness), and an average impact value is 50J. Under the same finished product condition, the impact toughness of a new steel grade is greatly improved if being compared with that of H13. Under parts of condition that requirements on the impact performance on the mandrel are harsh, H13 steel can be replaced so as to improve production efficiency and lower production cost.

Description

technical field [0001] The invention relates to a new type of hollow mandrel rod material for a continuous rolling pipe mill. The steels currently on the market are high-alloy hot work die steels such as H13 and H11, while the steel type involved in the present invention is a low-alloy structural steel. technical background [0002] The mandrel is an important tool that participates in the rolling deformation of the steel pipe in the production of seamless steel pipes. Its main function is to form a closed annular pass with the roll, so as to reduce the diameter and wall of the capillary, and at the same time eliminate the spiral indentation on the inner and outer surfaces of the perforated capillary. It is a high value-added bulk consumable spare part to improve the roughness and flatness of the inner and outer surfaces of the waste pipe. Due to the high service temperature of the mandrel when it is working, it is also subject to high axial tensile stress and radial compr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/24C22C33/04C21D8/10B21B25/00
Inventor 李丰吴晓春闵永安张恒华许珞萍严泽生庄钢赵晓林文玉成
Owner SHANGHAI UNIV