You are here: Home / Products / Raise Boring Tool / Raise Boring Drill Pipe / Raise Boring Machine High Toughness 4330V Forging Steel Drill Pipe for Mine Tunnel Engineering

Raise Boring Machine High Toughness 4330V Forging Steel Drill Pipe for Mine Tunnel Engineering

Share to:

Raise Boring Machine High Toughness 4330V Forging Steel Drill Pipe for Mine Tunnel Engineering

Name: Raise Boring Machine High Toughness 4330V Forging Steel Drill Pipe for Mine Tunnel Engineering
Brand: ETERNAL
Rating: 5.0 (46 reviews)

1. Size: OD 12-7/8'', TR 10-1/2''

2. Service:Customized
3. Material: Alloy steel 4330V
4. Product Procedure:Forging,heat treatment,lathe machining
5. Heat treatment: Quenching and tempering

6.Weight: 740kg
7.Lead time:60 days after receiving the advance payment
8.Payment type :50% after signing the contract, and 50% before shipment
7.Payment terms:FOB/EXW/FCA/CIF，etc
8.Package: wooden box
9.MOQ: 10 pcs
10.Quality Warranty Certificate: chemical composition and mechanical properties test certificates

Availability:

Quantity:



Inquire Add to Basket

Model:
RBM drill pipe-OD 12-7/8'', TR 10-1/2'',Customized
Brand:
ETERNAL

Product Description

4330V is a high-strength alloy steel. Thanks to its excellent balance of strength and toughness as well as good hardenability in large cross-sections, it is widely used for heavy-duty drill pipes in mining and tunnel engineering, especially in raise boring machine applications.

We could manufacture 8'' to 15''drill pipes,which have excellent mechanical property and impact value.They could be installed on machines of Atlas Copoc,Robbins,NFM,etc .

Application

Core Application Scenario: Raise Boring Drilling

In mining and tunnel engineering, 4330V steel is mainly used to manufacture drill rods and stabilizer rods for raise boring machines.

Connecting drill bits and drilling rigs

For areas inaccessible to drilling rigs, 4330V drill rods are adopted to transmit torque and axial thrust to the reaming bit.

Adaptation to deep complex strata

It is particularly suitable for high-stress strata featuring great depth (over 1000 meters), hard rock and strong abrasiveness.

drill pipe for Mine tunnel from ETERNAL Tunneling industry

Core Advantage

High Strength and Toughness: After quenching and tempering treatment, its tensile strength stably exceeds 1000 MPa, and the yield strength ranges from 896 MPa to 965 MPa. It maintains stable performance under extremely high tensile, compressive and torsional stresses.

Excellent Wear Resistance: Its overall hardness reaches 321–388 HBW, and the uniform tempered microstructure formed by heat treatment enables it to resist severe abrasion on the outer wall of drill pipes caused by hard rocks and abrasive formations, effectively extending service life.

Deep Hardenability: Alloying elements including nickel, chromium, molybdenum and vanadium are added to 4330V steel. This ensures that drill pipes with large diameters and thick wall thicknesses (45–50 mm for example) achieve core mechanical properties consistent with those of the surface, eliminating the risk of internal fracture caused by the defect of hard surface but soft core.

Impact Resistance: The material features a high impact energy of no less than 90 joules. It can absorb impact loads during drilling operations and prevent brittle fracture of drill pipes under complex stress conditions.

AISI 4330V Mechanical property

Tensile Strength: 1100–1200 MPa

Yield Strength: ≥1034 MPa

Elongation: ≥15 %

Reduction of Area: ≥45 %

Room Temperature Impact Energy (Akv): ≥45 J

Hardness: 30–34 HRC

Production Process

Smelting of 4330V Raw Material

Combined Process: Adopt the integrated process of electric arc furnace primary smelting + ladle furnace (LF) refining + vacuum degassing (VD). This process can effectively remove sulfur, phosphorus, gases and inclusions.

C	Cr	Ni	Mo	V
0.26-0.33%	0.8-1.1%	1.4-1.7%	0.15-0.25%	0.05-0.1%

Forging and Preliminary Machining

After heating, pure steel ingots are forged into drill pipe blanks of required specifications by hot forging. For raise bore drill pipes, they are processed into large-diameter thick-walled pipes at this stage, to guarantee sufficient rigidity and wear resistance.

Quenching and Tempering Heat Treatment

Step 1: High-temperature quenching. Heat the drill pipes to 860℃ and hold the temperature for 6 hours to fully convert the internal structure into austenite. Then rapidly quench them in warm water below 70℃ to form hard yet relatively brittle martensite structure.

Step 2: High-temperature tempering. Reheat the quenched drill pipes to 620℃, keep warm for 6 hours, and then cool them in air.

Finish Machining and Finished Products

Drill pipes are processed to final dimensions via finish machining after heat treatment.

Special Thread Design: To meet the rapid assembly and disassembly demands in mine and tunnel construction, one end of the drill pipe is machined with three-start external taper thread, and the other end is equipped with matching internal taper thread. This design features fewer screw turns and accurate thread alignment, greatly improving construction efficiency.

Final Inspection: Strict mechanical property tests and non-destructive flaw detection are conducted on finished products to ensure all factory-delivered drill pipes are safe and reliable.

Function in shafts

Torque transmission: Transmit the torque of the drilling rig to the drill bit to break rock.

Tension bearing: Withstand the huge tensile load of the entire drill string and reamer bit during reaming.

Stabilization & guiding: Ensure the verticality of the shaft bore, prevent hole deviation and hole collapse.

Flushing and cuttings removal: Hollow structure delivers flushing fluid, cools the drill bit, and carries away rock cuttings.

Drill Rod Common Size