How to qualify a Welding Procedure

The qualification of welding procedures is necessary to ensure that the selected welding parameters can produce sound welds and complying with project specification.  Qualification typically involves a combination of destructive and nondestructive testing (DT and NDT).  When a particular code, such as AWS D1.1 or ASME Section IX is used, the code will indicate the type and numbers of tests necessary in order to qualify the welding procedure. But incase of you are not required to follow specific codes or standards, it is advisable that you do some kind of testing if you are developing a new procedure.  Many fabricators … Continue reading How to qualify a Welding Procedure

How to handle and store Construction Material? | 6 Pro Tips on Handling and Storing Construction Materials

Did you know that 30% of construction materials go to waste? This totals to a big amount of money that could easily be saved and used for other projects. Don’t be part of the construction industry that carelessly partakes in … Continue reading How to handle and store Construction Material? | 6 Pro Tips on Handling and Storing Construction Materials

Weld porosity, herringbone, wormhole, crater pipe

What is Porosity in Welding? Porosity is a type of weld-defect that specifically refers to the entrapment of external gases within a welded joint, most commonly oxygen. As the molten metal of a weld cools and solidifies, the external gas will either enter in a weld and become trapped internally thus creating cavities or it will be forced out of the weld leaving behind visible holes, gas-mark, or pits, or crater pipe on the surface of the weld. The presence of porosity can severely affect the overall integrity and strength of the weld meaning, that a porosity-contaminated weld will nearly always be … Continue reading Weld porosity, herringbone, wormhole, crater pipe

Nelson curves and HTHA damage

High Temperature Hydrogen Attack (HTHA) is one of the Damage Mechanisms that affects Hydrogen service Steel equipment which exists mainly at Refineries, Methanol and Ammonia plants . HTHA occurs at elevated temperatures with Hydrogen service. HTHA vulnerability for equipment depends on three major factors, namely, Metallurgy type (composition), operating temperature and Hydrogen partial pressure. HTHA is mostly found in equipment made from Carbon Steel as well as Carbon ½ Mo. Damage mechanism· HTHA can occur in hydrogen atmosphere at elevated temperatures (at least 400 °F or 204 °C) and a hydrogen partial pressure of pH2 > 3.45 bar.· Thermal dissociation … Continue reading Nelson curves and HTHA damage

What is steel tempering?

Tempering of steels Tempering is an ancient metallurgical heat treatment technique by this procedure steels are heated below the eutectoid transformation temperature (A1 line) and cooling in the air. Rapid cooling is taking part in the specimen. At 400°F (205°C) epsilon martensite converts into carbide to orthorhombic cementite, low carbon martensite into BCC ferrite, and the retained austenite into lower bainite respectively. At 800°F (427°C) continuous formation of cementite is materialized immaculately. Tempering is necessitated after quenching or hardening to decrease some of the extents of hardness and to undertake better toughness by lessening the hardness of the steel. By … Continue reading What is steel tempering?

SWL vs WLL on Lifting equipment

The term Safe Working Load, (SWL) has been the cornerstone of engineering, particularly with respect to load carrying equipment, for many years. It was generally considered to be the minimum breaking load of a component divided by an appropriate factor of safety giving a ‘safe’ load that could be lifted or be carried. In Australia the use of Safe Working Load (SWL) for cranes, hoists and winches was universally used throughout all industries and referenced in legislation and the Australian Standards. The Wikipedia definition of SWL is:  Safe Working Load (SWL) sometimes stated as the Normal Working Load  (NWL) is the mass or force that a piece of lifting … Continue reading SWL vs WLL on Lifting equipment