PLATE - TRI-BRAZE® - MICROSTRUCTURE
Tri-Braze® Micro-cleanliness:
Each heat of Tri-Braze® is specially processed using state-of-the-art desulfurizing techniques to obtain very low sulfur contents and to achieve "sulfide shape control". Through this process any sulfide inclusions remaining in the steel are modified so that they resist deformation during hot working and remain virtually globular or spherical in nature. In this form, inclusions have much less effect on the steel's ductility and the directional characteristics are substantially reduced. The elimination of sulfide stringers removes a source of commonly known weak points at which many types of steel failures originate.
Through this special processing, Tri-Braze® has enhanced quality and greatly improved properties. Some of the benefits are noted below:
1. Internal Cleanliness: The internal cleanliness is greatly improved through virtual elimination of most inclusions. Tri-Braze® will meet the most restrictive ASTM Ultrasonic Testing Specification (ASTM A578-82 Level 1) for internal cleanliness.
2. Notch Toughness: Charpy V-Notch impact values are higher than when conventional processing practices are used. While both the longitudinal and transverse impact energies are higher, it is the transverse values which show the greatest improvement. The transverse energy levels approach those in the longitudinal direction of a non-desulferized heat.
3. Formability: In conventionally processed steels a much larger minimum bend radii is needed when the bend axis is parallel to the plate length (transverse bend) than when the bend axis is perpendicular to the plate length (longitudinal bend). In many cases, these so called "hard way" bends were avoided due to possible breakage. Through sulfide shape control processing' "hard way" bends are no longer the hard way. Bends can be made in either direction with equal ease. As a general rule, minimum bend radii recommended for longitudinal bends in conventionally treated steels can be used for transverse bends in desulfurized steels.
» See Forming Tri-Braze®
Tri-Braze® Microstructure
The microstructure of Tri-Braze® consists mainly of tempered martensite. In the heavier sections a lower bainitic structure is also present toward the center portion through the thickness.
An etched photomicrograph shows the presence of the Titanium Carbo-Nitrides. These small Titanium Carbo-Nitrides are randomly dispersed throughout the martensitic matrix and are extremely hard and improve the abrasion resistance of the steel.
Torching and Welding:
Due to the virtual elimination of most nonmetallic inclusions, the initiation sites for crack propagation along the torched edge and/or in the heat affected zone, are also eliminated. This in turn enhances the torching characteristics and the weldability of Tri-Braze®, due to the virtual elimination of most non-metallic inclusions, the initiation sites for crack propagation along the torched edge, and/or in the heat affected zone, are also eliminated.
» See Cutting Tri-Braze®
» See Welding Tri-Braze®
Microstructure
Tri-Braze® microstructure, tempered martensite, nital etch (400x)