Part 1: Characteristics of Heavy Weight Wide-Flange Structural Shapes

Heavyweight W14 structural shapes were developed for use as column members and have been so used for many years. Because columns are loaded primarily in compression, there has been little concern about the toughness of these structural shapes. However, designers have begun to specify heavyweight shapes for noncolumn members that may be subjected to tensile stresses, where toughness can be an important consideration to minimize the probability of fracture.

This paper presents information concerning the chemical, microstructural, and mechanical (including fracture toughness) properties for heavyweight wide-flange structural shapes of A36, A572 Grade 50 and A588 Grade A steels. A total of 63 pieces of these grades of W14 structural shapes weighing from 342 to 730 lb/ft (509 to 1086 kg/m) was obtained for this investigation. In many instances the samples were obtained from both ends of an ingot so that the effects of location within an ingot could be evaluated. The ASTM-specified location is the web-quarterthickness for tension-test specimens and the flange quarterthickness for Charpy V-notch (CVN) specimens. The microstructure, partial chemical composition, tensile properties and CVN properties were determined at these two locations, and also at the web and flange midthickness locations. In addition, nil-ductility temperatures were determined for selected samples.

Part 2: Data Survey on Mechanical Property Characterization of A588 Steel Plates and Weldments

This paper is a response on the part of the Pressure Vessel Research Committee to a request by pressure vessel manufacturers and users for information about the mechanical properties, especially toughness, that can be expected of steels in the ASTM A588 specification. It was recognized that although this steel is not used in pressure vessels themselves, it was and is widely employed for pressure vessel supports and other types of construction related to the pressure vessel industry. In this context the steel is used because it has a somewhat higher yield strength than the ordinary carbon-manganese steels, such as A36, and because there is a general belief that improved toughness can be obtained from this grade. Some of the material purchased has had toughness specifications applied to it and the experience of fabricators has been that the material can meet these specifications. In many instances, the requirements have been moderate, 15 ft-lb at 40°F, (20 J at 5°C) and the material can be purchased to this specification. Other fabricators have purchased A588 steels without such a specification under the assumption that good toughness will naturally be characteristic of this product. In most instances, however, it is the higher strength level obtainable that has made its selection attractive.