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Tianjin Yuantai Derun Pipe Manufacturing Group Co., Ltd., established in March 2002, is the biggest manufacturer specializing in  ERW square&rectangular tube/pipe, hollow section structure pipe, galvanized pipe and spiral welding pipe in China. Annual output reaches 5 million tons.Yuantai Derun has 59 production lines of black ERW pipe, 10 production lines of galvanized pipe and 3 production lines of spiral welding pipe. Square pipe from 20*20*1mm to 500*500*40mm, rectangular pipe from 20*30*1.2mm to 400*600*40mm,  welded pipe from 2”—60” can be manufactured. Yuantai Derun can manufacture square rectangular pipes as per the standards of ASTM A500, JIS G3466, EN10219, DIN2240, BS1387, AS1163.

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January 1993

Key team members of Yuantai Derun group began technical job in Tianjin Daqiuzhuang tube factory.

June 2002

Tianjin Yuantai Industry & Trade Co., Ltd. was founded, specialize in square, rectangular hollow steel pipe, hot galvanized welded (hot dip galvanized) square tube, the registered capital is USD 10 million.

May 2004

One of Yuantai subsidiaries Tangshan Lituo Steel Tube Co., Ltd. was established, specialize in square rectangular straight welded hollow steel pipe, registered capital is USD 10 million.

April 2005

Yuantai Steel Square Pipe Co. Ltd. was established, specialize in square welding hollow steel tube and galvanized tube, the registered is USD 2 million.

March 2010

Tianjin Yuantai Runxiang commercial trade company was established, specialize in strip steel trade, galvanized pipe agent, etc., the registered capital is USD 2 million.

March 2010

Tianjin Yuantai Derun pipe manufacturing group Co. Ltd. was formally established, marking that the production of high-frequency welded black, galvanized square pipe, spiral welded pipe, pipe logistics and pipe trade as one of the large-scale joint enterprise Yuantai Derun group was formally established, the group registered capital is USD 20 million.

March 2010

Tianjin Yuantai Derun Investment Co., Ltd. was formally established, specialize in steel pipe industry chain,lower industry mergers and acquisitions and industrial real estate development, the registered capital is USD 2 million.

August 2013

Tianjin Derun Runfeng pipe manufacturing Co. Ltd was established, specialize in hot galvanized (hot galvanizing) processing business, the registered capital is USD 8 million.

March 2015

Tianjin Yuantai Yuanda anti-corrosion insulation pipe Co., Ltd. was established, specialize in spiral welded pipe production and sales, the registered capital is USD 2 million.

August 2015

Tangshan Yuantai Derun Pipe Co., Ltd. was established, specialize in steel strip, steel pipe trade, registered capital is USD 1 million.

March 2016

Tianjin Yuantai Derun International Trade Co., Ltd was established,mainly engaged in international import and export business for Yuantai Group, registered capital is USD 2 million.

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Precautions for the production of special-shaped steel pipes-news-TIANJIN YUANTAI DERUN PIPE MANUFACTURING GROUP CO., LTD-
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Precautions for the production of special-shaped steel pipes
Precautions for the production of special-shaped steel pipes

Special-shaped steel pipes are a particularly important form and type of seamless pipes. They are widely used in various construction projects, building construction, and decoration. Special-shaped steel pipes are always found to be broken during production and main sales. That is, many links in the production are not done well. Another reason is insufficient ingredients and improper proportions of chemical elements.


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1. Small longitudinal cracks

The small longitudinal cracks on the surface of special-shaped steel pipes are less than 200mm in length, less than 3mm in width, and less than 0.3mm in depth.

2. Peak cracks

All the cracks occur at 5-60mm from the edge of the lower surface of the special-shaped steel pipe. The macroscopic direction is perpendicular to the rolling direction and is in the shape of a "peak".

3. Edge cracks

The cracks mainly occur at 20-80mm from the edge of the special-shaped steel pipe. The shape is multiple parallel longitudinal cracks of different sizes. The rule is that the thicker and wider the specifications of the special-shaped steel pipe, the more serious such defects.

4. Inclusions and scars

Inclusions and scars are distributed regularly, and the phenomenon is obvious after edge flame peeling crack inspection or ingot scratch flame cleaning.

For the fiber structure and crystal defects such as dislocation and vacancy in steel, annealing or normalizing are generally used to eliminate them. The purpose of annealing is to refine the grains, eliminate structural defects, reduce hardness, improve plasticity, and facilitate cold processing. Annealing equipment is indispensable in the production of cold-drawn special-shaped steel pipes. Therefore, formulating a suitable annealing process is a necessary condition to ensure that the structure of the special-shaped steel pipe is qualified and the product does not have fracture defects.