General Requirements for Rolled Steel Plates, Shapes, Sheet Piling, and Bars for Structural Use

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Introduction to ASTM Structural Steel Requirements

The American Society for Testing and Materials (ASTM) has established comprehensive standards that govern the production and quality control of structural steel products. These general requirements provide a unified framework that applies to rolled steel plates, shapes, sheet piling, and bars unless specifically modified by individual material specifications. This standardization ensures consistency across the steel industry while maintaining the flexibility to address specific application needs.

Applicable ASTM Steel Specifications

The general requirements outlined in this document apply to an extensive range of ASTM specifications, each designed for specific structural applications and performance requirements.

Table 1. ASTM Steel Specifications Coverage

ASTM Designation	Title of Specification
A 36/A 36M	Structural Steel
A 131/A 131 M	Structural Steel for Ships
A 242/A 242 M	High-Strength Low-Alloy Structural Steel
A 283/A 283 M	Low and Intermediate Tensile Strength Carbon Steel Plates, Shapes, and Bars
A 284/A 284 M	Low and Intermediate Tensile Strength Carbon-Silicon Steel Plates for Machine Parts and General Construction
A 328/A 328 M	Steel Sheet Piling
A 441/A 443 M	High-Strength Low-Alloy Structural Manganese Vanadium Steel
A 514/A 514 M	High-Yield Strength, Quenched and Tempered Alloy Steel Plate Suitable for Welding
A 529/A 529 M	Structural Steel with 42 000 psi {290 MPa) Minimum Yield Point (12.7 mm Maximum Thickness)
A 572/A 572 M	High-Strength Low-Alloy Columbium-Vanadium Steels of Structural Quality
A 573/A 573 M	Structural Carbon Steel Plates of Improved Toughness
A 588/A 588 M	High-Strength Low-Alloy Structural Steel with 50 ksi (345 MPa) Minimum Yield Point to 4 in. Thick
A 633/A 633 M	Normalized High-Strength Low-Alloy Structural Steel
A 656/A 656 M	Hot-Rolled Structural Steel, High-Strength Low-Alloy Plate with Improved Formability
A 678/A 678 M	Quenched and Tempered Carbon Steel Plates for Structural Applications
A 690/A 690 M	High-Strength Low-Alloy Steel H-Piles and Sheet Piling for Use in Marine Environments
A 699	Low-Carbon Manganese-Molybdenum-Columbium Alloy Steel Plates, Shapes, and Bars
A 709	Structural Steel for Bridges
A710/A710 M	Low-Carbon Age-Hardening Nickel-Copper-Chromium-Molybdenum-Columbium and Nickel-Copper-Columbium Alloy Steels
A 769	Electric Resistance Welded Steel Shapes
A 786/A 786 M	Rolled Steel Floor Plates
A 808/A 808 M	High-Strength Low-Alloy Carbon, Manganese, Columbium, Vanadium Steel of Structural Quality with Improved Notch Toughness
A 827	Plates, Carbon Steel, for Forging and Similar Applications
A 829	Plates, Alloy Steel, Structural Quality
A 830	Plates, Carbon Steel, Structural Quality, Furnished to Chemical Composition Requirements

Primary Structural Steel Standards

The foundational specifications include ASTM A36 for general structural steel, A131 for marine applications, and A242 for high-strength low-alloy applications. These specifications represent the most commonly used structural steel standards in construction and engineering applications.

Specialized Steel Applications

Advanced specifications such as A514 for high-yield strength quenched and tempered alloy steel plates, A588 for weathering steel applications, and A709 for bridge construction demonstrate the comprehensive scope of ASTM structural steel standards. Each specification addresses specific performance requirements while maintaining compatibility with these general requirements.

Steel Product Classifications and Definitions

Understanding the precise definitions and classifications of steel products is essential for proper specification and application. The ASTM standards provide clear criteria for distinguishing between different product categories.

Steel Plate Classifications

Steel plates represent flat-rolled products that meet specific dimensional criteria. When ordered by thickness, plates must exceed 200 mm in width with thickness over 6 mm, or exceed 1200 mm in width with thickness over 4.5 mm. Alternative weight-based classifications specify plates over 200 mm width weighing 47.1 kg/m² or heavier, or plates over 1200 mm width weighing 35.3 kg/m² or heavier.

It's important to note that slabs, sheet bars, and skelp products, despite potentially meeting these size criteria, are not classified as plates under these specifications. Additionally, coiled products remain excluded from these qualifications until they are cut to specific lengths.

Structural Shape Categories

The classification system for structural shapes provides clear distinctions based on dimensional characteristics and intended applications.

Structural-size shapes encompass rolled flanged sections where at least one cross-sectional dimension measures 75 mm or greater. These products typically serve as primary load-bearing members in construction applications.

Bar-size shapes include rolled flanged sections with maximum cross-sectional dimensions less than 75 mm, generally used for lighter structural applications or as components in larger assemblies.

Wide-Flange Shape Designations

The "W" shape designation applies to doubly-symmetric wide-flange shapes used as beams or columns, characterized by substantially parallel inside flange surfaces. Shapes with similar nominal weight and dimensions but non-parallel inside flanges may also qualify as "W" shapes if their average flange thickness matches the standard "W" shape specifications.

"HP" shapes serve specialized applications as bearing piles, featuring flanges and webs of equal nominal thickness with essentially equal depth and width dimensions.

Standard Shape Classifications

"S" shapes represent doubly-symmetric shapes manufactured according to dimensional standards established in 1896 by the Association of American Steel Manufacturers for American Standard beam shapes. These historical standards continue to influence modern structural steel production.

"M" shapes encompass doubly-symmetric shapes that cannot be classified under the "W," "S," or "HP" designations, providing flexibility for specialized applications.

Channel shapes include "C" shapes produced according to the 1896 American Standard channel specifications and "MC" shapes for channels not meeting standard "C" shape criteria.

"L" shapes represent both equal-leg and unequal-leg angles, providing versatility for various connection and bracing applications.

Manufacturing Processes and Requirements

The manufacturing of structural steel products follows established processes that ensure consistent quality and performance characteristics across different applications and environments.

Steel Production Methods

Unless otherwise specified in individual material specifications, structural steel must be produced using open-hearth, basic-oxygen, or electric-furnace processes. These primary steelmaking methods provide the foundation for consistent chemical composition and metallurgical properties.

Additional refining processes, including vacuum-arc-remelt (VAR) and electroslag-remelt (ESR), are permitted to enhance steel purity and performance characteristics. These advanced refining techniques prove particularly valuable for critical applications requiring superior cleanliness and homogeneity.

Plate Production Methods

Steel plates can be manufactured through two primary approaches: discrete cut lengths of flat product or cutting from coiled material. Plates produced from coil stock are cut to individual lengths from coiled products and furnished without additional heat treatment, though stress relieving is not considered heat treatment for these purposes.

Heat Treatment Requirements and Options

Heat treatment plays a crucial role in achieving desired mechanical properties and performance characteristics in structural steel products. The specifications provide flexibility in determining who performs heat treatment while maintaining strict quality requirements.

Heat Treatment Responsibility

Heat treatment may be performed by the manufacturer, processor, or fabricator unless specifically designated in the material specification. When manufacturers or processors conduct heat treatment, they must follow the specifications exactly as outlined in the applicable material standard.

Purchasers may specify alternative heat treatment procedures provided they do not conflict with material specification requirements. This flexibility allows for optimization based on specific application needs while maintaining compliance with safety and performance standards.

Fabricator Heat Treatment Options

When fabricators perform normalizing operations, they may accomplish this through uniform heating for hot forming processes. The heating temperature for hot forming should not significantly exceed the normalizing temperature to prevent adverse effects on material properties.

Manufacturers and processors retain the option to heat treat materials through normalizing, stress relieving, or combined normalizing and stress relieving processes even when no heat treatment is specifically required, provided the final products meet all material specification requirements.

Advanced Cooling Techniques

With purchaser approval, cooling rates faster than air cooling are permissible for toughness improvement. However, plates receiving accelerated cooling must subsequently undergo tempering in the temperature range of 595°C to 705°C to optimize the final microstructure and mechanical properties.

Chemical Analysis and Quality Control

Rigorous chemical analysis protocols ensure that structural steel products meet specified composition requirements and maintain consistent quality across production runs.

Standard Analysis Requirements

The manufacturer must conduct chemical analysis of each heat to determine the percentages of carbon, manganese, phosphorus, sulfur, and any other elements specified or restricted by the applicable specification. This analysis should utilize test samples taken during the heat pouring process whenever possible to ensure representative results.

Special Remelting Process Analysis

When vacuum-arc-remelting or electroslag remelting processes are employed, special analysis procedures apply. A heat is defined as all ingots remelted from a single primary melt. The heat analysis must be obtained from one remelted ingot or its product from each primary melt, provided the primary melt heat analysis meets specification requirements.

If the primary melt heat analysis fails to meet specification requirements, individual test samples must be taken from the product of each remelted ingot. In all cases, analyses from remelted material must conform to the heat analysis requirements of the applicable specification.

Metallurgical Structure Specifications

When applications require fine austenitic grain size, specific testing and acceptance criteria ensure optimal material performance characteristics.

Grain Size Requirements

Steel requiring fine austenitic grain size must achieve a grain size number of 5 or finer as determined by the McQuaid-Ehn test. This determination follows the procedures outlined in Plate IV of Methods E 112, involving carburizing for 8 hours at 925°C.

Acceptance Criteria

Conformance to the specified grain size requires that 70% of the grains in the examined area meet the size requirements. One test per heat provides the basis for acceptance, ensuring consistent metallurgical quality across production runs.

Edge Preparation and Finishing Options

Understanding the various edge preparation methods available for steel plates helps ensure proper selection for specific applications and fabrication requirements.

Mill Edge Characteristics

Mill edge represents the normal edge produced by rolling between horizontal finishing rolls. This edge type does not conform to any definite contour, and mill edge plates typically feature two mill edges with two trimmed edges.

Universal Mill Edge Features

Universal mill edge results from rolling between both horizontal and vertical finishing rolls. Universal mill plates, sometimes designated as UM plates, combine two universal mill edges with two trimmed edges, providing enhanced dimensional control.

Alternative Edge Preparations

Sheared edge plates receive trimming on all edges through shearing processes, while gas cut edges result from flame cutting operations. Special cut edges involve enhanced flame cutting practices, including pre-heating, post-heating, or both, to minimize stresses, prevent thermal cracking, and reduce edge hardness. In special cases, machining may produce special cut edges.

Steel Classification by Deoxidation Practice

Different deoxidation practices produce steels with distinct characteristics suitable for various applications and performance requirements.

Rimmed Steel Properties

Rimmed steel contains sufficient oxygen to produce continuous carbon monoxide evolution during ingot solidification, resulting in a case or rim of metal virtually free of voids. This characteristic provides specific advantages for certain forming and surface quality applications.

Semi-Killed Steel Characteristics

Semi-killed steel represents incompletely deoxidized steel containing sufficient oxygen to form enough carbon monoxide during solidification to offset solidification shrinkage. This balance provides controlled properties for specific applications.

Capped Steel Features

Capped steel begins as rimmed steel but limits the rimming action through early capping operations. Mechanical capping uses heavy metal caps on bottle-top molds, while chemical capping involves aluminum or ferrosilicon additions to molten steel in open-top molds.

Killed Steel Advantages

Killed steel undergoes complete deoxidation through strong deoxidizing agents or vacuum treatment, reducing oxygen content to levels preventing carbon-oxygen reactions during solidification. This process produces steel with superior cleanliness and consistency.

Conclusion

These general requirements for rolled steel plates, shapes, sheet piling, and bars provide the foundation for consistent quality and performance across numerous ASTM specifications. By establishing unified standards for manufacturing processes, heat treatment, chemical analysis, and metallurgical structure, these requirements ensure that structural steel products meet the demanding needs of modern construction and engineering applications while maintaining the flexibility to address specific performance requirements through individual material specifications.