Views:6 Author:Site Editor Publish Time: 2017-12-20 Origin:Site
Seamless steel pipes and tubes are standard commodities which must be subject to special standard. The ASTM A179 is the standard for seamless cold-drawn low-carbon steel heat exchange and condenser tubers. They are widely used in chemical engineering, petroleum, steel and automatic mobile and many other industrial equipment. And specially for the bent, flatting, flaring and flange required parts of steel tubes.
Before ordering and making the steel pipes with A179 standard what information should be known to make them well.
The material: Low carbon seamless steel pipes contain SAE1010, SAE1020, SAE1040; St35, St37, St45; E255, E355ect. However, under A179 standard SAE1010 and St35 is popularly adopted. The chemical composition shall be conformed to the following requirement as below.
Carbon, % 0.06-0.18
Manganese, % 0.27-0.63
Phosphorus, max, % 0.035
Sulfur, max, % 0.035
The sizes: The specification containing outside diameter(OD), inside diameter(ID), wall thickness(WT). And the tolerance of them. The outside diameter and inside diameter covers from 3.2mm to 76mm. Tubing smaller in outside diameter and having a thinner wall than indicated in this specification is available. Mechanical property requirements do not apply to tubing smaller than 3.2mm in outside diameter or with a wall thickness under 0.4mm. And customers should supply the length requirement. The fixed length or random length.
Delivery conditions: The steel pipes must be heat treatment under this standard ASTM A179. The temperature after final cold draw is 650℃ or higher. The seamless tubes with A179 shall have a hardness number not exceeding 72HRB.
Surface Condition：Finished tubes are not allowed with scale. But a slight amount of oxidation will not be considered as scale.
How to certify the steel pipes’ quality?
No test no result of the quality. While ASTM A179 seamless steel pipes are finished we must do mechanical tests. The flattening test, faring test, flange test, hardness test and hydrostatic test are required.
So for purposes of design, the following tensile properties many be assumed:
Tensile strength, min, ksi [Mpa] 47
Yield strength, min, ksi[Mpa] 26
Elongation in 2 in. Or 50mm, min, % 35