Bethlehem Steel Capillary Mayari ASTM A242-87 TYPE 1 (MAYARI-R), Steel Capillary

Bethlehem Steel Capillary Mayari ASTM A242-87 TYPE 1 (MAYARI-R) 3/16 to 3/4 in. thick, Steel Capillary plate Product Information -:- For detailed product information, please contact sales. -: Bethlehem Steel Capillary Mayari ASTM A242-87 TYPE 1 (MAYARI-R) 3/16 to 3/4 in. thick, Steel Capillary plate Synonyms -:- For detailed product information, please contact sales. -:

Bethlehem Steel Mayari ASTM A242-87 TYPE 1 (MAYARI-R) 3/16 to 3/4 in. thick, steel plate Product Information -:- For detailed product information, please contact sales. -: # **Bethlehem Steel Mayari® R ASTM A242-87 Type 1 (3/16" to 3/4" thick) High-Strength Low-Alloy Weathering Steel Plate** --- ## **1. Overview** Bethlehem Steel's **Mayari R**, conforming to **ASTM A242-87 Type 1**, is a premium high-strength, low-alloy (HSLA) **weathering steel** plate. Engineered specifically for the **3/16" to 3/4" (0.1875" to 0.75") thickness range**, this material is distinguished by its ability to form a tight, protective, and self-healing oxide layer (patina) when exposed to the atmosphere. The "Mayari" name is a proprietary Bethlehem brand, synonymous with enhanced performance weathering steel. This product delivers a superior combination of **increased yield strength** (50 ksi minimum), **excellent atmospheric corrosion resistance** (typically 4-8 times that of plain carbon steel), and **good weldability and formability**. It was designed for structural applications where maintenance-free longevity, aesthetic appeal of a natural rust finish, and weight savings through higher strength are paramount. --- ## **2. International Standards** This product conforms to the following key standards, with specific reference to its weathering characteristics: * **Primary Standard: ASTM A242 / A242M - 87:** Standard Specification for High-Strength Low-Alloy Structural Steel. * **Type 1:** Denotes steel supplied with enhanced atmospheric corrosion resistance. The chemistry is specifically tailored to form a protective patina. * **Proprietary Designation:** **Mayari R** (the "R" often signifies "rolled" or a specific grade within the Mayari family). This was Bethlehem's trade name for a superior weathering steel meeting and exceeding ASTM A242. * **Related Specifications:** * **ASTM A588 / A588M:** Another common weathering steel specification. Mayari R's performance and chemistry are comparable, often positioned as a premium alternative. * **AASHTO M270 Gr. 50W:** The standard for weathering steel in highway bridge construction. --- ## **3. Chemical Composition (Typical, % by Weight)** The unique chemistry is the source of its weathering and strength properties. Key alloying elements promote the formation of a dense, adherent rust layer. | Element | Content (Typical / ASTM A242 Type 1 Range) | Role & Implication | | :--- | :--- | :--- | | **Carbon (C)** | 0.10% - 0.19% | Kept low for weldability and toughness. Strength derived from other elements. | | **Manganese (Mn)** | 0.80% - 1.25% | Primary strengthener and aids in deoxidation. | | **Phosphorus (P)** | 0.04% - 0.10% | **Key weathering element.** Promotes the formation of the protective phosphate-rich patina layer. Higher than in non-weathering steels. | | **Sulfur (S)** | 0.05% max | Controlled for weldability. | | **Silicon (Si)** | 0.25% - 0.50% | Enhances strength and atmospheric corrosion resistance. | | **Copper (Cu)** | **0.25% - 0.40%** | **Key weathering element.** Essential for initiating and stabilizing the protective oxide layer. Provides core corrosion resistance. | | **Chromium (Cr)** | **0.40% - 0.70%** | **Key weathering element.** Greatly enhances atmospheric corrosion resistance and strengthens the patina. | | **Nickel (Ni)** | **0.20% - 0.40%** | Improves toughness, corrosion resistance, and balances the effects of copper. | | **Vanadium (V)** | 0.01% - 0.10% (Optional) | Often added for grain refinement and precipitation strengthening (especially in later versions). | | **Key Characteristic:** | **Cu + Cr + Ni + P System.** The synergistic combination of these elements creates a dense, tightly adherent oxide layer that retards further corrosion, unlike the flaky, porous rust of carbon steel. | | --- ## **4. Physical & Mechanical Properties (As-Rolled)** Properties are for the as-rolled condition, providing a high-strength base material. | Property | ASTM A242 Specification Minimum | Typical Value for Mayari R (3/16"-3/4") | | :--- | :--- | :--- | | **Yield Strength (min)** | **50 ksi (345 MPa)** | Typically 50-60 ksi. **~40% stronger than A36.** | | **Tensile Strength** | **70 ksi min (485 MPa)** | Typically 70-85 ksi. | | **Elongation in 2" (min)** | 18% (for 3/4" and under) | Typically 20-25%. Maintains good ductility. | | **Yield-to-Tensile Ratio** | N/A | Typically 0.71 - 0.78. Favorable for some forming. | | **Modulus of Elasticity** | 29,000 ksi (200 GPa) | | | **Corrosion Resistance** | **Dramatically Superior.** Forms a protective patina. Atmospheric corrosion rate is typically **4 to 8 times slower** than that of plain carbon steel (A36) in rural, industrial, and marine atmospheres. | | | **Surface Finish** | Hot-rolled mill scale. The initial rusting process begins upon exposure and evolves over 1-3 years to a stable, dark brown patina. | | --- ## **5. Key Features & Advantages** * **Maintenance-Free Durability:** The primary advantage. Eliminates the need for painting in most atmospheric exposures, drastically reducing lifecycle costs. * **Higher Strength-to-Weight Ratio:** 50 ksi minimum yield allows for weight savings and thinner sections compared to A36, reducing material and freight costs. * **Aesthetic Appeal:** The evolving and eventual stable russet-brown patina is architecturally desirable for many exposed structures. * **Good Weldability & Formability:** Despite its alloy content, it is readily weldable with proper procedures and can be cold formed. * **Proven Long-Term Performance:** Decades of service in bridges and buildings validate its performance claims. --- ## **6. Product Applications** Mayari R was specified for iconic exposed structures where durability and appearance were critical. * **Bridges & Highway Structures:** Exposed girders, fascia beams, and railings (AASHTO M270 50W applications). * **Architectural & Building Facades:** Exposed structural frames, curtain wall supports, and sculptural elements. * **Transmission & Utility Towers:** Unpainted power line towers and substation structures. * **Heavy Equipment & Mining:** Exposed structural components on equipment where paint maintenance is difficult. * **Marine & Coastal Applications (with caution):** For structures in the atmospheric zone (splash zone and immersion require different materials). --- ## **7. Fabrication & Processing Notes** * **Cutting & Shearing:** All standard methods apply. Plasma and laser cutting are excellent. Flame-cut edges will rust preferentially initially but will eventually blend. * **Forming:** Good cold formability. Minimum bend radii are similar to other 50 ksi steels (approx. 2.5t - 3t for 90° bends). More springback than mild steel. * **Welding:** **Weldable, but requires attention.** * **Electrodes:** Use weathering steel matching electrodes (e.g., E7018-W1, AWS A5.5) to ensure the weld metal also forms a protective patina and matches the base metal's corrosion and mechanical properties. * **Preheat:** Generally not required for this thickness range under normal conditions, but recommended for thicknesses over 1/2" or in cold weather. * **Cleanliness:** Remove all mill scale from the weld zone for best results. * **Surface Preparation & Weathering Process:** * **Initial State:** Mill scale is not protective and will flake off. For a uniform patina, the scale is often removed by abrasive blasting to a "near-white" finish (SSPC-SP10) before erection, allowing the steel to weather evenly from bare metal. * **Wet/Dry Cycles:** The patina forms fastest with regular wet/dry cycles. Stagnant moisture or constant immersion prevents proper patina formation. * **Design Considerations:** * **Run-off:** Design must prevent ponding of water and allow free drainage. * **Galvanic Corrosion:** Isolate Mayari R from dissimilar metals (e.g., aluminum, stainless steel) to prevent galvanic corrosion. * **Initial Stain:** The weathering process produces rust runoff that can stain adjacent concrete or masonry. This is temporary but must be considered. --- ## **8. Comparison & Legacy** * **vs. ASTM A588:** The performance is very similar. Mayari R was Bethlehem's branded, high-quality version of this class of steel, often with tighter property control. * **vs. ASTM A606 (Type 4 - Weathering):** A thinner sheet product; Mayari R is the heavy plate counterpart. * **vs. A36 (Painted):** Higher initial cost but eliminates recurring painting costs. Lifecycle cost analysis typically favors weathering steel for exposed structures. * **Legacy:** Mayari R steel was used in countless landmark bridges and buildings. Its production legacy continues with **Cleveland-Cliffs Inc.** (which acquired Bethlehem assets) and other mills producing ASTM A588/A242 material. --- **Disclaimer:** *This profile describes the traditional product. The Mayari R trademark is historical. For current procurement, specify **ASTM A242 Type 1** or **ASTM A588** for plate in this thickness range, and consult the producer's data sheets. Ensure welding and design practices follow the latest AASHTO or AWS guidelines for weathering steel. The corrosion resistance multiplier is environment-dependent; consult corrosion data for specific service locations.* -:- For detailed product information, please contact sales. -: Bethlehem Steel Mayari ASTM A242-87 TYPE 1 (MAYARI-R) 3/16 to 3/4 in. thick, steel plate Specification Dimensions Size： Diameter 20-1000 mm Length <4611 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: Bethlehem Steel Mayari ASTM A242-87 TYPE 1 (MAYARI-R) 3/16 to 3/4 in. thick, steel plate Properties -:- For detailed product information, please contact sales. -:

Applications of Bethlehem Steel Capillary Mayari ASTM A242-87 TYPE 1 (MAYARI-R) 3/16 to 3/4 in. thick, Steel Capillary plate -:- For detailed product information, please contact sales. -: Chemical Identifiers Bethlehem Steel Capillary Mayari ASTM A242-87 TYPE 1 (MAYARI-R) 3/16 to 3/4 in. thick, Steel Capillary plate -:- For detailed product information, please contact sales. -:

Packing of Bethlehem Steel Capillary Mayari ASTM A242-87 TYPE 1 (MAYARI-R) 3/16 to 3/4 in. thick, Steel Capillary plate -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Capillary drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1082 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition