Cooling Technique of Stainless Steel LNG System Pipe
Time：2015.10.30
Source: http://www.sssshangshang.com
Author：www.sssshangshang.com
As is known to all, stainless steel pipee has a wide application in the field of construction, oil and water transmission and decoration. Especially the stainless steel LNG system pipe occupies a more important place because it has taken the responsibility of conveying the liquid natural gas used in many families. All kinds of stainless steel pipe are made from stainless steel materials and stainless steel LNG system pipe is without exception. Considering the need of natural gas is large, the pipes should have large diameter in order to achieve high flow. With large diameter stainless steel LNG system pipe, the transportation of liquid natural gas can have high efficiency and the requirements can be achieved. Among large diameter stainless steel LNG system pipe production process, the most important should be cooling technique. The cooling technique is an important link in the production process of stainless steel tube. There will be a lot of quality problems because of the incorrect process method. Therefore, we should pay special attention to the cooling process. There are many key points you should know:
Firstly, super cooled austenite stainless steel tube is very stable, with a very high hardenability. Even if cooled by air-cooling, the martensite can be obtained. But air cooling will result in the tool surface oxidation, and there may be eutectoid carbide precipitation. Therefore, when cooling the large diameter stainless steel LNG system pipe, we should not use air-cooling as far as possible.
Secondly, for large and complex stainless steel pipes like stainless steel LNG system pipe, in order to reduce distortion and cracking, they should have pre-cooling treatment during quenching. But the time should be preciously controlled. According to the shape of the stainless steel pipe, the time can be controlled within several seconds to one minute. The premise is not precipitating secondary carbides.
Thirdly, quenching temperature of large diameter stainless steel LNG system pipe should be not exceed 650 ° C, in order to prevent precipitation of carbides and pearlite transformation occurs.
Fourthly, because retained austenite after quenching temperature is isothermal and more stable, it should be tempered for four times in order to get high-quality large diameter stainless steel LNG system pipe of good performance.
That is all for cooling process of stainless steel LNG system pipe. Actually, not only the LNG pipe but also many other pipes are in need of such process. If you want to buy stainless steel pipe of high cost performance, you can contact us by logging in www.sssshangshang.com. High-quality products with reasonable price are available here.
Firstly, super cooled austenite stainless steel tube is very stable, with a very high hardenability. Even if cooled by air-cooling, the martensite can be obtained. But air cooling will result in the tool surface oxidation, and there may be eutectoid carbide precipitation. Therefore, when cooling the large diameter stainless steel LNG system pipe, we should not use air-cooling as far as possible.
Secondly, for large and complex stainless steel pipes like stainless steel LNG system pipe, in order to reduce distortion and cracking, they should have pre-cooling treatment during quenching. But the time should be preciously controlled. According to the shape of the stainless steel pipe, the time can be controlled within several seconds to one minute. The premise is not precipitating secondary carbides.
Thirdly, quenching temperature of large diameter stainless steel LNG system pipe should be not exceed 650 ° C, in order to prevent precipitation of carbides and pearlite transformation occurs.
Fourthly, because retained austenite after quenching temperature is isothermal and more stable, it should be tempered for four times in order to get high-quality large diameter stainless steel LNG system pipe of good performance.
That is all for cooling process of stainless steel LNG system pipe. Actually, not only the LNG pipe but also many other pipes are in need of such process. If you want to buy stainless steel pipe of high cost performance, you can contact us by logging in www.sssshangshang.com. High-quality products with reasonable price are available here.
