Substructure for drilling rig-2

1

Pin shaft φ160

112.27.250.01

42CrMo Alloy Steel (Quenched & Tempered, Hardness HRC45-50)

1. Journal surface wear due to insufficient lubrication and high-speed rotation; 2. Fatigue cracking from cyclic torque and dynamic load impact.

1. Apply high-pressure anti-wear grease to the journal surface every 50 operating hours; 2. Conduct magnetic particle testing (MPT) annually to detect hidden fatigue cracks.

2

Pin shaft φ120x430

112.27.250.03

42CrMo Alloy Steel (Precision Machined & Stress-Relieved)

1. Corrosion pitting in offshore saltwater or high-humidity environments; 2. Shear stress damage from misaligned load transmission.

1. Apply marine-grade anti-corrosion coating to exposed ends; 2. Ensure precise alignment during assembly to avoid eccentric load bearing.

3

Shaft φ230

112.27.250.09

40CrNiMo Alloy Steel (Forged & Heat-Treated)

1. Torsional fatigue from long-term high-torque transmission; 2. Wear at keyway due to repeated key insertion/removal during maintenance.

1. Monitor torque values during operation to avoid overloading; 2. Use hydraulic tools for key assembly/disassembly to reduce keyway damage.

4

Shaft φ110

112.27.250.15

40Cr Alloy Steel (Quenched & Tempered)

1. Bearing seizure-induced shaft surface scratches; 2. Thermal fatigue cracking from extreme temperature fluctuations (desert/arctic drilling).

1. Inspect bearing condition monthly and replace worn bearings promptly; 2. Insulate shaft in extreme temperature environments to reduce thermal stress.

5

Shaft φ150

112.64.320.01

42CrMo Alloy Steel (Precision Ground)

1. Abrasive wear from drilling cuttings and dust ingress; 2. Loosening of fit with mating parts due to vibration, leading to impact damage.

1. Install dust-proof seals at both ends of the shaft; 2. Re-check fit clearance quarterly and rework or replace if exceeding 0.2mm.

6

Pin shaft φ63X160

112.45.245.03

35CrMo Alloy Steel (Heat-Treated)

1. Wear at contact surface due to repeated rotational movement; 2. Corrosion from drilling fluid immersion.

1. Lubricate contact surface with drilling fluid-resistant grease; 2. Clean and dry the pin shaft after exposure to drilling fluid, then reapply lubricant.

1

Balance frame for raising up

112.27.276.00

Q690 High-Strength Low-Alloy Steel (Welded & Stress-Relieved)

1. Weld joint fatigue cracking from uneven load distribution; 2. Bending deformation from overloading beyond rated capacity.

1. Conduct ultrasonic testing (UT) of weld joints every 6 months; 2. Strictly comply with rated load limits; install load sensors for real-time monitoring.

2

Hoisting wire line

112.70.275.00

High-Strength Steel Wire Rope (IWS Structure, Galvanized)

1. Abrasive wear from contact with pulley grooves and sharp edges; 2. Fatigue failure from repeated bending and tension cycles.

1. Inspect wire rope for broken strands, wear, and corrosion daily; replace if broken strands exceed 3 in 1 lay; 2. Ensure pulley groove diameter matches wire rope diameter (diameter ratio ≥12).

3

Pulley φ960

112.27.270.00

ZG35CrMo Cast Steel (Pulley Body) + GCr15 Bearing Steel (Bearings)

1. Pulley groove wear from long-term wire rope friction; 2. Bearing seizure due to lubrication failure and dust contamination.

1. Inspect pulley groove wear monthly; re-machine if wear depth exceeds 10% of wire rope diameter; 2. Lubricate bearings with high-temperature anti-wear grease every 100 operating hours.

4

Pulley φ570

112.27.288.00

ZG310-570 Cast Steel (Pulley Body) + GCr15 Bearings

1. Impact damage from load swing during hoisting; 2. Corrosion of pulley body in humid or offshore environments.

1. Install anti-swing devices to minimize load oscillation; 2. Apply marine-grade anti-corrosion coating to pulley exterior and inspect quarterly.

5

Pulley φ700

112.64.340.00

ZG35CrMo Cast Steel (Pulley Body) + GCr15 Bearings

1. Torsional fatigue of pulley hub from cyclic torque; 2. Wear of bearing raceways due to misalignment.

1. Conduct UT of pulley hub annually to detect fatigue cracks; 2. Ensure pulley shaft alignment error ≤0.1mm/m during assembly.

6

Raise-down unit

112.45.240.00

42CrMo Alloy Steel (Mechanical Components) + Cast Iron (Housing)

1. Gear wear from insufficient lubrication and metal particle contamination; 2. Hydraulic seal failure (if hydraulic-driven) leading to pressure loss.

1. Replace lubricating oil every 500 operating hours and install oil filters; 2. Inspect hydraulic seals for leaks daily and replace worn seals promptly.

7

Double pad eye

112.42.246.00

Q690 High-Strength Steel (Forged)

1. Fatigue cracking at load-bearing points from repeated hoisting cycles; 2. Wear at pin hole from contact with lifting pins.

1. Conduct MPT annually to detect fatigue cracks; 2. Lubricate pin hole with anti-wear grease before each use and inspect wear monthly.

1

Hydraulic system (including four hydro cylinder and pipeline, control box)

YG05-00

Carbon Steel (Pipeline) + Alloy Steel (Cylinder Rod) + Aluminum Alloy (Control Box)

1. Pipeline corrosion and blockage from hydraulic oil contamination; 2. Cylinder rod wear from dust and impact damage.

1. Filter hydraulic oil regularly and keep the oil tank sealed to prevent contamination; 2. Install protective sleeves on cylinder rods and inspect for damage weekly.

2

Cylinder clamp

112.42.245.03

Carbon Steel Q235B (Zinc-Plated)

1. Loosening of clamping force due to vibration, leading to cylinder displacement; 2. Corrosion of clamp body in humid environments.

1. Re-torque clamping bolts monthly using a calibrated torque wrench; 2. Inspect zinc plating for damage and touch up with anti-corrosion paint as needed.

3

Long double pipe clamp 18

F7-7-93

Ductile Iron (QT450-10) + Rubber (Lining)

1. Rubber lining aging and cracking from high temperature and oil erosion; 2. Clamp body deformation from over-tightening.

1. Replace rubber lining every 12 months or if cracking is detected; 2. Follow recommended torque values during installation to avoid over-tightening.

1

Casing block

112.27.272.00

ZG35CrMo Cast Steel

1. Abrasive wear from contact with rotating casings; 2. Impact damage from casing lowering/raising operations.

1. Apply anti-wear welding overlay to contact surfaces; 2. Install buffer pads at casing entry/exit points to reduce impact.

2

Web joint

112.27.285.00

Q690 High-Strength Steel (Welded)

1. Weld joint fatigue from cyclic substructure vibration; 2. Corrosion in high-humidity or saltwater environments.

1. Conduct UT of weld joints every 6 months; 2. Apply anti-corrosion coating to all surfaces and inspect quarterly for damage.

3

Little platform

112.61.290.00

Q355B Carbon Steel (Hot-Dip Galvanized, Anti-Slip Surface)

1. Anti-slip surface wear from personnel and equipment traffic; 2. Corrosion of support brackets from environmental exposure.

1. Re-coat anti-slip surface annually or if wear is detected; 2. Inspect support brackets for corrosion and tightness monthly.

1

Foot block

112.42.245.04

High-Strength Rubber + Steel Plate

1. Rubber aging and hardening from high temperature and oil erosion; 2. Steel plate corrosion from environmental moisture.

1. Replace rubber component every 12 months; 2. Apply anti-corrosion coating to steel plate and keep the area dry.

2

Clip φ30

111.03.100.02

Spring Steel 65Mn (Heat-Treated)

1. Spring fatigue from repeated opening/closing; 2. Corrosion leading to loss of clamping force.

1. Inspect clamping force monthly; replace if clamping is loose; 2. Store spare clips in a dry environment to prevent corrosion.

3

Board 150x100

112.45.240.01

Q235B Carbon Steel (Pickled & Oiled)

1. Bending deformation from uneven load bearing; 2. Corrosion from drilling fluid and environmental moisture.

1. Ensure uniform load distribution when placing equipment; 2. Clean drilling fluid residue regularly and apply anti-corrosion paint.

4

Board 129x100

112.45.240.02

Q235B Carbon Steel (Pickled & Oiled)

1. Abrasive wear from contact with moving parts; 2. Edge damage from impact during installation.

1. Install wear-resistant pads at contact points with moving parts; 2. Use proper lifting tools during installation to avoid edge impact.

5

Foot block 87x20x20

F8-3-93

Nylon 66 + Steel Insert

1. Nylon wear from long-term load bearing and friction; 2. Steel insert corrosion from moisture ingress.

1. Inspect nylon wear monthly; replace if wear exceeds 3mm; 2. Seal the interface between nylon and steel insert to prevent moisture ingress.