AISI 4330V

AISI 4330V is a vanadium-modified nickel-chromium-molybdenum low-alloy steel supplied in the quenched and tempered condition. It contains about 0.30 to 0.34 per cent carbon, 1.65 to 2.00 per cent nickel, 0.75 to 1.00 per cent chromium, 0.40 to 0.50 per cent molybdenum and 0.05 to 0.10 per cent vanadium. It is used mainly for forged drilling tools and other heavy sections that need high strength with good toughness.

The difference is the vanadium addition. AISI 4330V carries 0.05 to 0.10 per cent vanadium that plain AISI 4330 does not. Vanadium carbides restrain grain growth at forging and austenitising temperature, which gives a finer final grain, deeper and more uniform hardening in thick sections, and better toughness at the same strength level.

Yes. 4330V, SAE 4330V, 4330V Mod, 4330 Mod and 4330 V Modified all describe the same vanadium-modified version of AISI 4330 used in the oil and gas industry. Purchase orders and mill certificates use the names interchangeably, so confirm the chemistry ranges rather than relying on the designation alone.

In the standard drilling tool condition supplied by Jiangyin Jiangnan Metal Co., Ltd., AISI 4330V gives 150 to 190 ksi (1,034 to 1,310 MPa) tensile strength, 140 to 180 ksi (965 to 1,241 MPa) 0.2 per cent proof stress, 15 per cent minimum elongation, 59 per cent minimum reduction of area and 35 to 39 HRC (331 to 370 HB). Lower strength tempers are available where a specification requires them.

Forgings are normalised at about 880 to 920 °C, austenitised at about 860 to 900 °C, quenched in oil or polymer according to section thickness, then tempered at 540 to 660 °C to reach the specified hardness band. Before rough machining the material is normalised and tempered at 677 °C maximum. The exact austenitising hold and tempering temperature are set from the section size and the required properties.

The largest use is drilling equipment: drill collars, drill jars, reamer bodies, stabilisers, subs and mandrels. It is also forged into wellhead and subsea components, valve bodies and stems, pump and compressor shafts, gear blanks, flanges, tube sheets and seamless rolled rings for heavy machinery.

It can be welded, but it is a hardenable alloy steel and needs control. Use a low hydrogen process, preheat to roughly 200 to 300 °C depending on thickness, maintain interpass temperature, and post weld heat treat below the final tempering temperature so the parent properties are not lost. Welding after final quench and temper always needs a qualified procedure.

Only if the hardness is controlled to NACE MR0175 / ISO 15156 limits, which are considerably lower than the 35 to 39 HRC drilling condition. Sour service parts must be ordered with the hardness cap, the heat treatment and any testing stated on the purchase order. State sour service at enquiry stage so the temper is planned for it.

4330V is the usual choice for drill collars and jars. Its lower carbon and vanadium grain refinement give better impact toughness and fatigue resistance in the thick wall sections that see bending and shock downhole. AISI 4340 reaches higher strength but is more notch sensitive and harder to weld.

Jiangyin Jiangnan Metal Co., Ltd. supplies AISI 4330V as forged round bars to 1,200 mm diameter, seamless rolled rings to 4,000 mm outside diameter, discs to 3,000 mm, shafts to 12 m long and single pieces up to 30 t. Material is EAF + LF + VD melted, ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388, and released with EN 10204 3.1 or 3.2 certification.

Email a drawing or a size list to sales@steelforgepieces.com or call +86 189 2135 9659. Include the grade, finished or rough dimensions, quantity, heat treatment condition, required hardness or mechanical properties, NDT class and certificate type. Quotations are normally returned within one working day.