The Evolution of HSLA Steels

Abstract

This paper reviews the evolution of HSLA steels, from their beginnings in 1929 with the development of weathering steels through the present highly sophisticated controlrolled microalloyed plate steels and microalloyed and intercritically heat-treated sheet steels. Some speculation is also included on possible future developments.Proceedings of a symposium sponsored by the Pyrometallurgical Commitee of

Mechanical Properties Laser Welding Automotive Steel Sheets

“…0.15%) of combination of elements of Al, Ti, Nb and V [13][14]. These elements are bonded to C and N. The size and percentage distribution of ferrite and the pearlite within the microstructure play an important role on the final mechanical properties [15][16]. Pearlite properties are influenced by nodule or colony size, ferrite strength and the thickness and spacing of the carbide laths [11].…”

The evolution of technology for structural materials over the last 50 years

“…The high-strength low-alloy (HSLA) steels emerged from work in the 1930s, and there are many derivatives (controlled-rolled, microalloyed, dual-phase, and so on). 14 The key observation is that with controlled rolling and precipitation hardening through small levels of alloying additions, the properties of the HSLA steels can far exceed those of plain carbon steels and also result in superior toughness and weldability. Maraging steels and very high strength steels were a focus of development in the 1960s.…”

Design of the thermomechanical control process of high strength low alloy (HSLA) steels

“…Vanadium carbides form at lower temperatures. Vanadium carbonitrides V(C, N) can be formed in ferrite and contribute to the strengthening by additional precipitation hardening [30].…”

“…Nickel, chromium and copper promote strengthening by increasing the hardenability of the steel. These elements also provide corrosion resistance [30].…”

“…The specimens were cut on the Rolling Direction-Normal Direction plane (RD-ND) and standard specimen preparation including grinding and polishing was conducted. The microstructure of the samples was revealed after etching, first in 2% nital for about 25 s and then in Beraha's reagent [30] (10 g Na2S2O3, 3 g K2S2O5 in 100 ml water) for 5 s. Grain size and shape measurements were performed on the middle of the specimens rolled section, and the Image J software [31] was employed for the image analysis on the SEM and AFM micrographs, in which more than 1000 grains were included at each material to reduce the measurement uncertainties. A nonparametric Kernel Density Estimator (KDE) approach was used to derive the equivalent circular grain diameter (ECD), feret grain diameter, and grain shape circularity distributions, using a fixed KDE bandwidth based on the plug-in method and an Epanechnikov kernel function [32].…”