What are Additives?What are the roles of Additives in lubricating oils? Additives are substances formulated for improvement of the anti-friction, chemical and physical properties of base oils (mineral, synthetic, vegetable or animal), which results in enhancing the lubricant performance and extending the equipment life. Combination of different additives and their quantities are determined by the lubricant type (Engine oils, Gear oils, Hydraulic oils, cutting fluids, Way lubricants, compressor oils etc.) and the specific operating conditions (temperature, loads, machine parts materials, environment).Amount of additives may reach 30%. Different types of Additives are , 1-Friction modifiers-Friction modifiers reduce coefficient of friction, resulting … Continue reading What are additives?

What the significance of adhesion testing in paints and coatings?What are the different test methods for adhesion testing? Good adhesion is critical to the integrity and long-term performance of a coating. Poor adhesion can result in failure, corrosion and contamination of surfaces or contents. So, it’s vitally important to undertake adhesion testing to assess the quality of the attachment between the dry paint film (coating) and its substrate. Test Methods: Pull-off Test — This procedure is accomplished by sticking a loading fixture perpendicularly to the coating, then slowly increasing tensile load until either the fixture and adhesive layers are removed or … Continue reading What is adhesion test

What is CTOD Test? CTOD test is used to determine fracture toughness (fracture resistance) of a material with an artificial crack, and a test to determine crack tip opening displacement to generate unstable fracture (limit CTOD value). It is usually carried out by loading a CTOD test specimen on a 3-point bending system as shown in below figure. These tests are made using a full-plate thickness specimen containing a machined notch which is extended by fatigue cracking.When a material having a defect is applied a load, a crack will propagate rapidly originating from the defect, resulting in fracture at a … Continue reading CTOD test, what is it?

Charpy V-notch (CVN) impact testing of the welded steel product. A required toughness level is commonly expressed for a particular test temperature (which may be different from the lowest anticipated service temperature) at which a minimum CVN impact energy value (KVmin), shall be achieved. The approximate relationship between the CVN energy-temperature curve and the fracture behavior of a welded steel component. Here are the samples of Typical impact test specimens will be machined and tested according to AWS D1.1, ASME B31.3, ASME VIII, and other construction codes. Notch location: 1 Centreline of the weld2 Fusion line3 In HAZ, 1mm from … Continue reading CVN Impact test specimens location for welded structure

Corrosion resistance is an important characteristic of Ni – base alloys and weldments. There are many acceptance tests specified in ASTM or EN ISO and other literature to evaluate the corrosion resistance of alloys for use in different environments. In this article, for common requirement in project specification. Intergranular corrosion, pitting, crevice or general corrosion assessment that will be took into discussion. I will try to describe the differences of the tests for applicable common standards (ASTM/ISO) and point out which alloys the tests are intended for, and recommends the most appropriate test when none is specified. The Huey test … Continue reading Corrosion Test Standard Selection

If welding is to be performed according to a welding procedure specification, it is possible that changing the electrode manufacturer will invalidate the approval of the procedure to the code/standard on which it was based. The manufacturer or ‘trade name’ … Continue reading Changing of Electrode Brand name or Trade name in welding essential variable