Five categories of steel structure engineering inspection

Steel structure engineering inspection includes raw materials, welding materials, welding parts, fasteners, welding seams, bolt ball joints, coatings and other materials of steel structure and special equipment and all specified test and inspection contents of the project. It mainly includes: nondestructive testing of steel structures, testing of main structure engineering, testing of mechanical properties of steel structures, testing of mechanical properties of steel structure fasteners, analysis of chemical composition of steel products, testing of coating materials, salt spray test, etc.

First, mechanical property testing

1, steel structure mechanical properties testing:

A. tensile testing (tensile strength, yield strength, elongation after fracture), bending test, impact test (normal temperature impact, low temperature impact, aging impact), hardness and other toughness and plastic properties of metal raw materials such as steel plates and round steel, tensile testing (yield strength, tensile strength), bending and other properties of steel bars. Z-direction tensile test of steel plate.

B welding procedure qualification of metal weldments, tensile and bending tests of steel weldments.

C metal hardness test is the ability of metal to resist local deformation, especially plastic deformation, indentation or scratch, and is an index to measure the hardness of metal materials. Hardness includes Vickers hardness, Richter hardness, Rockwell hardness and Brinell hardness.

2, steel structure fastener mechanical properties testing

Torque coefficient of bolt connection pair, fastening axial force, tensile strength (yield strength, tensile strength), wedge load test, bolt and nut load test, bolt and washer hardness and other properties, and slip resistance coefficient detection of bolt connection plate.

Second, the steel chemical composition analysis

Chemical composition analysis of steel is divided into spectral analysis and wet analysis.

III. Testing of Coating Raw Materials

1. Routine inspection of coatings, internal and external wall coatings, fireproof coatings and anticorrosive coatings. Routine inspection items include: state, color and appearance, viscosity, outflow time, fineness, specific gravity, hiding power, drying time, nonvolatile content, specular gloss, hardness, flexibility, bending resistance, adhesion, impact resistance, water resistance, chemical reagent resistance, heat resistance, sag resistance, damp heat resistance, wear resistance, salt fog resistance and aging resistance.

2. Steel structure coating quality inspection. Conventional inspection items include: steel structure coating appearance inspection, steel structure coating adhesion inspection and steel structure coating thickness inspection.

IV. Salt spray test

Salt spray test is an environmental test that mainly uses the artificial simulated salt spray environmental conditions created by salt spray test equipment to assess the corrosion resistance of products or metal materials. The purpose of salt spray test is to examine the salt spray corrosion resistance quality of products or metal materials. The determination methods of salt spray test results include rating determination method, weighing determination method, corrosion occurrence determination method and corrosion data statistical analysis method.

Salt spray tests mainly include: neutral salt spray test (NSS test), salt spray test (SS test), acetic acid salt spray test (ASS test), copper accelerated vinegar instinct test, and high temperature wet heat test.

Five, nondestructive testing test

Non-destructive testing (NDT) is a general term for all technical means that use acoustic, optical, magnetic and electrical characteristics to detect whether there are defects or non-uniformities in the tested object without damaging or affecting the performance of the tested object, give information such as the size, location, nature and quantity of defects, and then determine the technical state (such as qualified or not, remaining life, etc.) of the tested object.