SQUARE AND RECTANGULAR HWS ENTERPRISE
ENTERS INTO CHINA TOP 500
MANUFACTURING ENTERPRISE

about us

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.

Learn More >>
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.

news

EXCEED EXCELLENT INNOVATION

Integrity

Rely on faith and trust to be achievement, make friends and be on the way all the time.

Innovation

Be low key but ambitious, look forward to the Era of Smart Production with intelligence, information and precision

Development

Create a century brand by the way of forging ahead and pursuing excellence

Dedication

Realize our vision and task, be valuable and feedback.

Some points should be paid attention to when the right angle tube is quenched-news-TIANJIN YUANTAI DERUN PIPE MANUFACTURING GROUP CO., LTD-
news

Home >> news

Some points should be paid attention to when the right angle tube is quenched
Some points should be paid attention to when the right angle tube is quenched

(1) The slender pipes should be hung vertically in a salt bath furnace or pit furnace as much as possible to reduce the deformation caused by their own weight.

(2) When right angle tube with different cross-sectional sizes are heated in the same furnace, the small pieces should be placed at the outer end of the furnace, and the large and small pieces should be timed separately and the small pieces will be released first.

(3) The amount of furnace installed each time should be adapted to the power of the furnace. When the amount of furnace installed is large, it is easy to press and warm, and the heating time needs to be prolonged. 

(4) For workpieces quenched with water or salt water, the quenching temperature shall be the lower limit; for workpieces quenched with oil or molten salt, the quenching temperature shall be the upper limit. 

(5) When performing dual-medium quenching, the time spent in the first quenching medium should be controlled according to the above three methods. The time for moving from the first quenching medium to the second quenching medium should be as short as possible, preferably 0.5-2s. 

(6) For right angle tube whose surface is not allowed to be oxidized or decarburized, they should be heated in a calibrated salt bath furnace or protective atmosphere furnace. If the conditions are not available, it can be heated in an air resistance furnace, but protective measures must be taken.

(7) After the right angle tube is vertically immersed in the quenching medium, it does not swing, but only moves up and down, and stops the stirring of the quenching medium.

right angle tube.jpg

(8) When the cooling capacity of the part with high hardness requirements of the pipe fittings is insufficient, the liquid spray cooling can be performed on the part while the whole is immersed in the quenching medium to improve the cooling speed.

(9) It must be placed in the effective heating area. The amount of furnaces, the method of furnace loading and the stacking form should ensure that the heating temperature is uniform and consistent, and will not cause distortion and other defects.

(10) When heating in the salt furnace, do not get too close to the electrode to prevent local overheating, and the distance should be more than 30mm. The distance from the furnace wall and the depth of immersion below the liquid surface should be more than 30mm.

(11) During graded quenching, the quenching temperature can be appropriately increased to increase the stability of the right angle tube austenite and prevent it from decomposing into pearlite.

(12) Structural steel and carbon steel can be directly loaded into the quenching temperature or heated in a furnace 20-30℃ higher than the quenching temperature. High-carbon high-alloy steel should be preheated at around 600°C, and then raised to the quenching temperature.

(13) For pipes with a deep hardened layer, the quenching temperature can be appropriately increased, and a lower quenching temperature can be selected for pipes with a shallow hardened layer.

(14) There shall be no dirt such as oil and soap liquid in the cooling water of the right angle tube. Under normal circumstances, the water temperature does not exceed 40 ℃, and the oil temperature does not exceed 80 ℃.