Non-magnetic Rod

I. Commonly used materials

1. 15-15HS Max: Low carbon content, containing elements such as nickel, chromium, nitrogen, manganese, molybdenum, etc., with good resistance to intergranular corrosion and pitting corrosion, low relative magnetic permeability, commonly used in the manufacture of non-magnetic drilling boats, stabilizers, etc. with a yield strength of not less than 140KSI.

2. P550 non-magnetic steel: mainly composed of elements such as iron, chromium, manganese, nitrogen, etc., it has a stable austenitic structure, low magnetic permeability, high electrical resistivity, and minimal eddy current loss in a magnetic field.

3. MP35N cobalt based alloy: It is a non-magnetic cobalt nickel alloy containing 35% nickel, 20% chromium and other elements. Even after cold rolling and aging treatment, it is non-magnetic and has good oxidation resistance and high strength.

II. Performance characteristics

1. High precision and smoothness: The non-magnetic rod has high dimensional accuracy and low surface roughness, with a general roughness of Ra0.8-Ra1.6 μ m. This helps reduce subsequent processing steps, improve the machining accuracy and surface quality of the parts.

2. Good comprehensive mechanical properties: It has high strength, high toughness, and wear resistance, such as the yield strength of P530 non-magnetic steel rod ≥ 850MPa, tensile strength ≥ 950MPa, and elongation ≥ 30%. It can be capable of withstanding various complex loads during the process of oil drilling.

3. Excellent non-magnetic performance: The magnetic permeability is extremely low. For example, P530 non-magnetic steel has a relative magnetic permeability of μ r<1.005 and a magnetic induction gradient of ≤ 0.04 μ T at a magnetic field strength of 16000 A/m. It can avoid interference with magnetic measuring instruments and ensure the accuracy of drilling parameter measurement.

III. Processing technology

Usually, the non-magnetic rod is first formed by hot rolling or forging, and then subjected to precision rolling, cold drawing or cold drawing processes to improve dimensional accuracy and surface smoothness. Finally, gas soft oxidation treatment may be carried out to enhance surface hardness, or high-temperature annealing may be performed to improve cutting performance.

IV. Application areas

Mainly used for manufacturing non-magnetic drill collars, sheaths for measurement while drilling (MWD) or logging while drilling (LWD) instruments, rotating directional drilling tools, stabilizers and other petroleum machinery components. These components play a key role in petroleum drilling, and the characteristics of non-magnetic rods help improve the efficiency and safety of petroleum drilling.