XM-19 Alloy Round Bar Diameter 5 - 300mm Stainless Steel Bar Hot
Rolled SS Bar
Overview of XM-19 Hot Rolled Stainless Steel Round Bar
XM-19 (also known as UNS S20910 or Nitronic 50) hot rolled
stainless steel round bar represents a breakthrough in austenitic
stainless steel technology, offering an unrivaled combination of
high strength and superior corrosion resistance at a competitive
price point. Engineered with a unique manganese-nitrogen 强化
composition, this alloy addresses the limitations of conventional
stainless steels like 316 and 317L, making it a preferred choice
across demanding industrial sectors.
Our XM-19 hot rolled round bars are available in a comprehensive
diameter range of 5mm to 300mm, catering to both small-scale
precision components and large industrial structures. The hot
rolling process enhances the alloy’s inherent properties, creating
a product with consistent mechanical performance, excellent
workability, and a surface finish optimized for subsequent
machining or direct application. Whether for marine hardware,
petrochemical equipment, or food processing machinery, these round
bars deliver reliable performance in environments where strength
and corrosion resistance are non-negotiable.
Key Properties of XM-19 Alloy Round Bar
The exceptional performance of XM-19 round bar stems from its
precisely balanced chemical composition and the structural
advantages imparted by hot rolling. Below is a detailed breakdown
of its core properties:
Chemical Composition
The unique alloying elements in XM-19 are responsible for its
superior strength and corrosion resistance. The following table
outlines its chemical composition limits:
| Element | Content Range (%) | Role |
|---|
| Carbon (C) | ≤ 0.06 | Maintains weldability and reduces carbide precipitation |
| Chromium (Cr) | 20.5 - 23.5 | Provides primary corrosion resistance and oxidation protection |
| Nickel (Ni) | 11.5 - 13.5 | Stabilizes the austenitic structure for toughness |
| Manganese (Mn) | 4.0 - 6.0 | Enhances strength and austenite stability |
| Molybdenum (Mo) | 1.5 - 3.0 | Improves resistance to pitting and crevice corrosion |
| Nitrogen (N) | 0.2 - 0.4 | Significantly boosts yield strength without compromising ductility |
| Niobium (Cb) | 0.1 - 0.3 | Refines grain structure and enhances mechanical properties |
| Vanadium (V) | 0.1 - 0.3 | Increases strength and improves creep resistance |
| Phosphorus (P) | ≤ 0.045 | Controlled impurity to prevent brittleness |
| Sulfur (S) | ≤ 0.03 | Minimized to ensure corrosion resistance and toughness |
Mechanical Properties
XM-19 hot rolled round bar outperforms traditional austenitic
stainless steels in both strength and versatility, maintaining
performance across a wide temperature range:
| Property | Unit | Minimum Value (Hot Rolled/Annealed) | High-Strength (HS) Variant |
|---|
| Tensile Strength | MPa | 690 | 1158 |
| Yield Strength (Rp0.2) | MPa | 380 | 1034 |
| Elongation (A5) | % | 35 | 15 |
| Brinell Hardness (HB) | - | ≤ 241 | 335 |
| Charpy Impact Toughness (Sub-zero) | J | Excellent | Good |
A key advantage of XM-19 is its retention of mechanical properties
at extreme temperatures—from cryogenic conditions to elevated
heat—without significant degradation. Unlike most austenitic
stainless steels, it remains non-magnetic even after cold working
or exposure to sub-zero temperatures .
Physical & Corrosion Resistance Properties
The physical characteristics of XM-19 complement its mechanical
strength, while its corrosion resistance sets a benchmark for
commercial stainless steels:
| Property | Specification |
|---|
| Density | 7.8 g/cm³ (0.285 lb/in³) |
| Melting Point | 1415 - 1450°C |
| Elastic Modulus | 190 - 210 GPa (26.2 x 10⁶ psi) |
| Thermal Conductivity (at 100°C) | 42.7 W/m-K (9.0 Btu/ft·hr·°F) |
| Thermal Expansion Coefficient (68-212°F) | 9.0 x 10⁻⁶ /°F |
| Corrosion Resistance | Superior to 316, 316L, 317, 317L; excellent resistance to general
corrosion, crevice corrosion, and sulfide stress cracking |
In annealed condition (1066°C), XM-19 exhibits enhanced crevice
corrosion resistance compared to 316L. For welded applications or
extreme corrosive environments, annealing at 1121°C further
optimizes its protective properties . Notably, it meets NACE
Standard MR 01-75/ISO 15156-3 requirements for sulfide stress
cracking resistance, making it suitable for oilfield "down hole"
equipment .
Hot Rolling Process & Quality Control
Our XM-19 round bars undergo a precision hot rolling process
designed to maximize the alloy’s potential while ensuring
dimensional accuracy:
- Raw Material Preparation: We source premium XM-19 billets produced
via ESU remelting or AOD/VOD to minimize impurities and ensure
chemical consistency .
- Controlled Heating: Billets are heated to 1177-1232°C at a
controlled rate (50-100°C/hour below 600°C) to prevent thermal
cracking, with of 20-30 minutes per 25mm thickness .
- Hot Rolling: Billets are rolled to diameter specifications
(5-300mm) within a temperature range of 980-1200°C, ensuring
optimal grain structure and mechanical properties .
- Annealing Treatment: Bars are annealed at 1066°C (standard) or
1121°C (corrosion-critical applications) followed by rapid cooling
to preserve austenitic structure .
- Dimensional Inspection: Each bar undergoes rigorous measurement to
ensure diameter tolerance of ±0.5mm (for <50mm) and ±1.0mm (for
>50mm), with straightness deviation ≤1mm/m.
Quality control every stage, including chemical analysis via
光谱分析,mechanical testing (tensile, hardness), and non-destructive
testing (ultrasonic inspection) to detect internal defects.
Applications Across Industries
The versatility of XM-19 hot rolled round bar makes it
indispensable in industries requiring both strength and corrosion
resistance:
- Oil & Gas: Used for downhole rigging, pump shafts, and valves,
thanks to its sulfide stress cracking resistance and high strength
.
- Marine Engineering: Ideal for boat shafts, marine hardware, and
offshore fasteners—outperforming 316 in saltwater corrosion
resistance while doubling yield strength .
- Chemical Processing: Valves, fittings, and heat exchanger
components benefit from its resistance to aggressive chemicals and
elevated temperatures .
- Food & Beverage: Sanitary pump parts and processing equipment
leverage its corrosion resistance and non-magnetic properties,
ensuring compliance with hygiene standards .
- Nuclear & Pulp/Paper: Utilized in nuclear fuel recycling and paper
mill machinery, where durability and chemical resistance are
critical .
- Medical: Suitable for non-magnetic implants due to its
biocompatibility and low magnetic permeability .
Specification & Order Information
Our XM-19 hot rolled round bars adhere to global standards and can
be customized to meet specific application needs:
| Specification | Details |
|---|
| Product Form | Hot rolled round bar |
| Diameter Range | 5mm - 300mm |
| Length | Standard: 3m, 6m; Custom lengths up to 12m available |
| Standards | ASTM A276, A479, UNS S20910, NACE MR 01-75 |
| Surface Finish | Hot rolled (black oxide) or pickled (matte) |
| Packaging | Anti-rust oil coating, waterproof paper wrapping, and steel
bundling for sea transport |
We offer additional services including cutting (plasma, laser, or
saw cutting), threading, and custom heat treatment to deliver
ready-to-use components.
Why Choose XM-19 Over Conventional Stainless Steels?
XM-19 outperforms traditional grades like 316L and 304 in key
metrics, offering tangible value:
| Feature | XM-19 | 316L | 304 |
|---|
| Yield Strength | 2x higher | Standard | Standard |
| Corrosion Resistance | Superior to 316L | Good | Moderate |
| Magnetic Properties | Non-magnetic after cold work | May become slightly magnetic | May become slightly magnetic |
| Temperature Performance | Excellent (cryogenic to high heat) | Limited at extremes | Limited at extremes |
| Cost-Efficiency | Higher strength-to-cost ratio | Lower initial cost, higher maintenance | Lower initial cost, shorter lifespan |
This performance advantage translates to reduced component weight,
longer service life, and lower maintenance costs—making XM-19 a
cost-effective solution for long-term applications .
Conclusion
XM-19 hot rolled stainless steel round bar (5-300mm diameter)
stands as a high-performance solution for industries demanding
uncompromising strength and corrosion resistance. Its unique alloy
composition, precision manufacturing, and versatile applications
make it a superior alternative to conventional stainless steels.
Backed by rigorous quality control and compliance with
international standards, our XM-19 round bars deliver consistent
performance in the most challenging environments.
