Carbon Equivalent Fundamentals in Evaluating the Weldability of Microalloy and Low Alloy Steels

Understanding the weldability of steel in relation to the use of carbon equivalent is very necessary for the welding industry. The study was poised to unearth the fundamentals of carbon equivalent as applied in evaluating the weldability of steel. The study used a two-stage design approach to address the problem of carbon equivalence weldability of steel, thus, survey and experimental. Two different steels were tested to ascertain their chemical composition which could inform carbon equivalent calculation, and the results revealed microalloy and low alloy steels respectively. In subjecting the microalloy steel to carbon equivalent analyses of the AWS and IIW coefficients;revealed a value (CEV) = 0.11 each, suggesting that this microalloy steel has excellent weldability;no preheating is required. A successful welding operation on this steel does not depend on preheating. Also, the average results of the low alloy steel revealed a value (CEV) = 0.37 and 0.32 respectively, suggesting that this type of steel has very good weldability and may require to preheat. It is recommended that welders have a general idea about the weldability of steel with regard to carbon equivalent calculation. In addition, they should understand the chemical compositions of steels they are dealing with.

Utilisation of Indigenous Ceramic Raw Materials for the Production of Water Closet

The fact is that Nigeria ceramic raw materials are underutilized as a result of inadequate information on the materials which limits the local production of water closet. The emphasis of this research was on the suitability of the physio-chemical properties of the abundant locally sourced ceramic raw materials from South-west Nigeria. The selected locally sourced raw materials included: kaolin, feldspar, silica and ball clay. The Physical properties carried out on the specimens produced include chemical analysis, shrinkage, porosity, bulk density, modulus of rupture, plasticity and viscosity. The physical property tests were done in accordance with (ASTM C). Standard and the chemical composition were identified by AAS spectrometer. However, the ratio of kaolin, feldspar, quartz and ball clay was varied in five major formulation represented as A, B, C, D and E. The clay, kaolin, quartz and feldspar used in this study were found to belong to alumina-silicate group suitable for the production of standard water closet. The samples’ properties met the required standards;hence, the materials were found suitable for production of water closet of acceptable standards. Composition A specimen gives the most suitable proportions for the production of water closet at 40% of kaolin, 25% of feldspar, 10% of quartz and 25% of ball clay respectively.