ASTM A276 TP316L Stainless Steel Round Bar , For Petrochemical Equipment

ASTM A276 TP316L Stainless Steel Round Bar , For Petrochemical Equipment

Overview

• ASTM A276 Type 316L is a low‑carbon (L) molybdenum‑alloyed austenitic stainless steel round bar for general engineering use. It offers improved resistance to pitting and crevice corrosion versus 304/304L, excellent weldability, and good toughness down to cryogenic temperatures.
• Designations: ASTM A276 (bars and shapes), ASTM A484 (general requirements), UNS S31603, EN 1.4404, X2CrNiMo17‑12‑2. For pressure-containing parts, ASTM A479 is often specified.

Typical chemical composition (wt%)

• C ≤ 0.030
• Cr 16.0–18.0
• Ni 10.0–14.0
• Mo 2.00–3.00
• Mn ≤ 2.0, Si ≤ 1.0, P ≤ 0.045, S ≤ 0.030, N ≤ ~0.10

Key properties

• Corrosion resistance: Strong general corrosion resistance; superior pitting/crevice resistance to 304L in chloride media due to 2–3% Mo. Not immune to chloride pitting/SCC, especially at elevated temperature; consider higher‑PREN alloys for aggressive seawater/brine.
• Mechanical (annealed, minimums typical per ASTM): Tensile ≥ 485 MPa (70 ksi), 0.2% yield ≥ 170 MPa (25 ksi), elongation ≥ 40%, hardness ≤ 95 HRB (≈ ≤ 217 HB).
• Physical: Density ~7.98 g/cm³; modulus ~193 GPa; thermal expansion (20–100°C) ~16.5 µm/m·K; thermal conductivity ~16 W/m·K; excellent toughness at cryogenic temperatures.
• Heat resistance: Good oxidation resistance in dry air up to about 870°C. Prolonged service in the 425–870°C range can reduce mechanical properties; L grade mitigates sensitization after welding.
• Magnetism: Essentially non‑magnetic when annealed; can become slightly magnetic after cold work.
• Weldability: Excellent; use matching fillers (e.g., ER316L/E316LSi). Post‑weld cleaning/passivation recommended; PWHT generally not required.
• Machinability: Work‑hardening austenitic grade; use sharp tooling, positive feeds, and generous coolant. Free‑machining variants exist but standard 316L limits sulfur for corrosion performance.

Manufacturing and supply conditions

• Processes: Hot‑finished and solution‑annealed & pickled (HRAP/black), cold‑drawn/bright, peeled/turned, centerless ground, precision ground, and polished.
• Finishes: Black (as‑rolled), bright‑drawn, turned/peeled, centerless ground, polished (e.g., 180/240/320/400/600 grit), mirror on request.
• Tolerances and QA: Dimensional and straightness tolerances per ASTM A484 (general requirements). Optional NDT (UT/eddy current), PMI, straightness control, low delta‑ferrite on request. MTC/COC to EN 10204 3.1 available.

Size range (typical offerings; customizable)

• Diameters: ~3 mm to 500 mm (1/8″ to 20″).
• Lengths: 3–6 m random (10–20 ft) or cut‑to‑length with tight straightness.
• Precision tolerances (e.g., h9/h10/h11) and ground shafts available upon request.

Typical applications

• Chemical and petrochemical equipment, heat exchangers, pumps and valves
• Marine fittings and shafts, coastal architectural components
• Food, beverage, and pharmaceutical process hardware
• Pulp and paper, textile, and dyeing equipment
• Cryogenic service and general engineering shafts/pins/fasteners