Corrosion and nanomechanical behavior of high strength low alloy steels

Abstract

The effect of electro‐slag refining (ESR) processing with niobium inoculation and increased carbon content of high strength low alloy steel was examined using electrochemical corrosion and nanomechanical test methods. The results indicate that ESR processing with niobium inoculation effectively improves the corrosion resistance of the steel by lowering the corrosion rate. This was shown due to refinement in grain size along with freedom from inclusions. Post test observation after potentiodynamic test revealed pitting corrosion attack of the steel processed through conventional melting process and its absence in case of ESR (with niobium inoculation) processed steel. Higher carbon content of 0.29 wt% effectively enhances the strength and hardness of the modified steel for use in larger rocket boosters. The lower Lc2 and lower friction coefficient (SFC) values obtained for the ESR processed (with niobium inoculation) steel during scratch test demonstrated that the hardness and wear resistance is better when compared to the conventional steel.

Tempering kinetics and corrosion resistance of quenched and tempered AISI 4130 medium carbon steel

“…The obtained polarization curves are shown in Figure 3a. Based on these curves, i corr (corrosion current density) was obtained by the Tafel extrapolation method [38][39][40][41] and is listed in Table 1. Then, i corr was plotted versus hardness in Figure 3b.…”

Corrosion behavior and mechanism of the high‐strength low‐alloy steel joined by multilayer and multipass welding method

“…High-strength low-alloy (HSLA) steels have been extensively used in marine engineering such as ship building, offshore platform construction, submarine pipelines, and so forth, because they generally outperform the rival materials in terms of weight-to-strength ratio, processing performance, corrosion resistance, as well as cost. [1][2][3][4][5] It is inevitable to join the HSLA steel through the welding process in engineering applications. Due to differences in the metallurgical effect, geometry, specific environmental conditions, or other aspects of the welded joints, any form of corrosion may occur, such as galvanic corrosion, pitting, stress corrosion cracking, intergranular corrosion, hydrogen cracking and microbial corrosion, and so forth.…”