Salt Quench Hardening: An Overview

This presentation will provide the general audience with an overview of salt quench hardening, the pros and cons of working with salt, the benefits of salt quenching, and some of the various processes as well as types of equipment used when working with salt quench applications. We will answer the question “why salt?” by comparing it to traditional oil quench applications, by considering the characteristics of salt and how it promotes hardenability, ductility, tensile and yield strength, and by looking at the benefits of salt for distortion control, heat extraction, ease of washing, and the “green” side of recycling. We will address equipment layout configurations and the ancillary pieces of equipment required for an efficient operation, based on production requirements with a consideration of the specific part weight, geometry and annual volume. We will touch on NFPA guidelines and general safety practices. Finally, we will look at various processes associated with quenching in salt – austempering and marquenching, and as we conclude the presentation, we will discuss how material and process changes can lead to engineering optimization opportunities for “light-weighting”, mechanical feature enhancements, and process reduction.

Distortion Control and Prevention by Fabrication Techniques in Cold Bent Steel Frame with Perforated Web

Cutouts are widely used in ships and offshore structures. Cutouts of big size are used mainly for inspection, passing pipes, and weight reduction. Some cutouts of small size may be used for various purposes, such as water hole in the web of stiffeners. The stiffeners with perforated web are the most commonly adopted structure members in the shipbuilding industry, and they are mainly fabricated by cutting and bending the frame to meet the requirements of desired design configuration. In ship production, the manufacture of the curved stiffener with holes is desirable to perforate first and then to bend the frame. This fabrication procedure is adopted for efficient production because of the layout of the production line. However, structural distortion and damage may occur during cold bending of the frames with perforated web, such as necking, wrinkling, and even crack initiation. This problem should be solved in ship production. In this study, cold bending experiments and finite element simulations were performed to analyze the deformation characteristics of curved frames with cutouts. A fabrication method is proposed to control the deformation in the cutouts during the bending process. In this method, the block cut out during the first step is filled in the hole and afterward the frame is bent. The results show that this method can control well the deformation localized around the hole during the bending process. It offers an important guidance for cold bending steel frames in ship production.

Cation disorder and octahedral distortion control of internal electric field, band bending and carrier lifetime in Aurivillius perovskite solid-solutions for enhanced photocatalytic activity

The overall photocatalytic activity shown by a semiconductor photocatalyst stems from a complex interplay of several critical factors that includes light absorption, carrier recombination dynamics, charge transfer resistance, lifetime of...

The metal halide structure and the extent of distortion control the photo-physical properties of luminescent zero dimensional organic-antimony(iii) halide hybrids

The structural tunability of 0D Sb Cl based hybrid perovskites and the underlying structural distortion mechanism affecting their emissive properties (PL emission energy, PLQY, Stokes shift) are demonstrated here.