API 7-1 P530 Non magnetic Drill collar for oil&gas downhole drilling
The Non-magnetic drill collar is made of a kind of low carbon high chrome-manganese alloy steel, material normally is P530 or P550 orP750 or higher grades, which is refined after strict chemical composition ratio and forged to achieve its mechanical properties, this kind of drill collar has superb mechanical properties of low permeability and high strength. Mainly used for down hole directional drilling.
Our Strict control of chemical composition and special forging process guarantee the excellent mechanical properties of our non magnetic drill collar.
Special Treatment on ID: Roller Burnishing. (after roller burnishing, a comprehensive layer come into being)
Increase the corrosion resistance properties;
Increase the surface hardness of bore up to HB400;
Increase surface finish of bore to Ra≤3.2μm
Test and inspection carried out on each bar during production :
Metallographic Test (Grain Size);
Corrosion Test (According to ASTM A262 Practice E);
Ultrasonic Test over the whole length of the bar (according to ASTM A388);
Relative magnetic permeability test;
Hot Spot Test;
Dimension Inspection, etc.