Application of oil‐in‐water emulsion in hot rolling process of brass sheet

Abstract

Purpose -The purpose of this paper is to develop a new oil-in-water (O/W) emulsion used for alpha phase brass, which can increase the antiwear and anti-galling abilities of the rollers, and improve the surface quality of the rolled brass sheet. The aim is to evaluate the tribological performance of new kind of O/W emulsion for the hot rolling of alpha brass, which provides the fundamental information for the selecting of new chemical group, and to understand the lubrication mechanism of the used rolling emulsion and to correlate the laboratory findings with those of industrial rolling of alpha phase brass. Design/methodology/approach -According to the hydrophile-lipophile balance theory and the evaluation results of friction, wear and lubrication using a four-ball tribometer, a novel O/W emulsion was developed for the hot rolling process of CuZn 32 (ASTM C26200) and CuZn 30 (ASTM C26000) alloys by controlling the composition of the emulsion, such as emulsifying, antiwear, extreme pressure, antirust and so on. By scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and roughness profile the tribological mechanism were studied. Findings -The production result proved that it was easy to control the accuracy and size of the brass sheet because of the emulsion-jet to the roller surface directly and in succession. Polyol with hydroxyl group is found to provide better lubrication and lower coefficient of friction. The actual hot rolling results proved that it was easy to control the accuracy and size of the brass sheet with the emulsion jet. The morphologies and roughness profile of the copper sheet surface were observed and measured by SEM and topographic meter under different lubricant conditions. The in situ results supported the selection of compositions of O/W emulsion. The suitable temperature of feed emulsion is over 208C.Research limitations/implications -The tribological mechanism of friction modified emulsion is not still clear. The thermal mechanical properties of rollers under this kind of emulsion are also worth studying in the future. Practical implications -Understanding the tribological behaviour of O/W emulsion, will be useful for emulsion chemists, tribologists and rolling mill users. Originality/value -The current study shows new compositions of O/W emulsion used for hot rolling of alpha phase brass.

Investigation of oxide scale on ferritic stainless steel B445J1M and its tribological effect in hot rolling

“…Emulsion possesses many favourable properties such as good lubricating ability, excellent cooling efficiency, non-flammability, low environmental effect and low cost, therefore, it has been widely used in hot rolling mills [38][39][40]. During hot rolling, the surface of the oxide scale is made up of asperities and when two surfaces are placed in contact only the tips of the asperities touch.…”

Flammability of emulsions on hot surfaces

“…), the local air flow, the surface shape, material and size, the fluid quantity, etc. (Hu et al, 2010). Data obtained using the test procedure described in SR EN ISO 20823:2004 have to be carefully integrated in selecting fluids and designing systems for reducing the fire risk induced by the probability of having locally high temperature surfaces and a fluid flow on them.…”

Synthesis of Emulsion by Using Vegetable Oil Modified by Titanium Dioxide (TiO2) Nanoparticles: A Peculiar Source for Synthesis of Bio‐Based Lubricant and Novel Approach to Enhance the Efficiency of Emulsion

“…All additives were added during continuous stirring for 3 h and temperature was maintained about 60-70°C. [17,20] A high-speed mixer (BPA) was employed for the preparation of emulsions. For 2% preparation of the emulsion, particular amount of water (98% by volume) and oil (2% by volume) was added simultaneously during agitation of a high-speed mixer for 2-4 min and temperature was maintained at 50-60°C.…”

“…Different explanations for the preparation of rolling oils and O/W emulsions have been given by different researchers. [17][18][19][20][21] The TiO 2 NPs have unique application like they have a competency to form a layer [22,23] on the surface of metal sheets (Figure 2) which protect metal sheets from rust. So in current research work, mustard oil-based emulsion modified by TiO 2 NPs provides better protection against rust.…”