To become an Inspection Engineer

Metallurgical science for the welding inspector.

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Metallurgical science is the study of internal structure of the metal, and the relationship between this structure and properties of metals. In metallurgical science, we are primarily interested in various changes that occur in metals when they are welded together. In particular, this applies to those changes that affect the mechanical properties of metals.

In this regard, the welding inspector should know the fundamentals of welding metal science. It seems unlikely that the welding inspector will be responsible for developing the technical conditions for alloys of base metals and weld metals, as well as for processing them. However, the understanding of the welding metal Continue reading →

Metallography and Heat Treatment of Metal

The polymorphic transformations in metals (Part 7).

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The transformation hardening of crystalline phases is a promising method of hardening metals. At temperatures above T0, the low-temperature modification of α is transformed into a high-temperature modification of β. In metals that have undergone an ordered polymorphic transformation upon cooling, heating can cause an inverse α → β transition without violating the coherence of the lattices. The characteristic feature of direct and reverse shear polymorphic transformation is a large temperature hysteresis. Along with the ordered polymers, the normal polymorphic transformation is also possible: the polygonization and Continue reading →

To become an Inspection Engineer

Impact toughness testing (Part 2).

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The Charpy impact test machine consists of the pendulum, support, lever, arrow and the scale. Since the task is to measure the energy absorbed during the destruction of the sample, the initial energy reserve is accumulated by raising the pendulum to the given height. After releasing the pendulum falls and continues its motion to the highest point on the other side of its trajectory. If it does not meet resistance, it rises to the height, which is called the point of zero energy absorption. When contracting a pendulum with the Charpy sample, some amount of energy is expended on the nucleation and propagation of the crack. Therefore, the pendulum rises to the height slightly below the point of zero energy absorption. The scale bar indicates the maximum height of this oscillatory motion Continue reading →

To become an Inspection Engineer

Welder Qualification Test (Part 8).

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The documentation execution is the only part of the welding control process. Another part is the welding inspector himself, whose task is to determine the quality of the product or part. The control is considered to be a kind of activity that is carried out after the production, but control of the welding works does not correspond to these views. The welding control includes activities that are performed before, during and after welding. Thus, the welding control performs both pre-emptive and corrective functions.

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Inspection of Welded Seams

The dependence of atoms ionization energy on the plasma temperature (Part 1).

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The existence of a welding arch is provided with the plasma conductivity thanks to which through the arch there passes welding current. In turn, the plasma conductivity is caused by existences of the electrons and ions which are formed of neutral atoms by their ionization. The intensity of the atoms ionization in specific conditions is provided with the size of the energy demanded for ionization of atom (Wi). Therefore, the knowledge of the size Wi and its dependence on concrete features of a welding arch is very important parameter.

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