Welding & Metallurgy Glossary

Burn-off is the loss of alloying elements from the weld pool by evaporation or oxidation in the arc. This makes the weld leaner in alloying elements and loses strength, toughness, or corrosion resistance. The welder must compensate for this loss with suitable filler materials or protective measures.

Peening means working the still-warm weld immediately after welding with a ball or needle hammer. Hammering stretches the weld and relieves shrinkage stresses that could otherwise cause cracking—the most important protection for crack-prone materials like cold-work steel and cast iron.

The temporal temperature drop per unit time during thermal treatment, which decisively determines the resulting microstructure and hardness. It governs diffusion processes during phase transition.

Quenching medium is a fluid or gas used for targeted heat removal during quenching. Its heat transfer coefficient determines the achievable hardness.

Cooling time is the time it takes for the weld metal to cool from a high temperature (e.g., 800 °C) to a lower one (e.g., 500 °C). It influences hardness formation and the phase structure of the steel.

A relevant thermal parameter for the cooling phase from 500 °C to 300 °C, used particularly to assess the embrittlement tendency of high-strength fine-grained structural steels.

The time required for a weld and its heat-affected zone to cool from 800 °C to 500 °C. This parameter is crucial for establishing the microstructure and preventing undesirable phase transformations.

A central welding metallurgical parameter describing the time required for a welded joint to pass through the critical temperature interval for phase transformations. It decisively determines the resulting microstructure in the heat-affected zone.

Deflection error occurs in hardness testing when the testing machine frame or the clamping device is elastically deformed. This leads to incorrect readings that must be corrected.

An official document from the manufacturer confirming that the delivered workpiece meets the specific requirements of the order and the applicable standards.

The abrasive mass flow indicates how much abrasive is fed per unit time in waterjet cutting. It determines the efficiency of material removal and tool wear.

Hard mineral particles, typically almandine garnet, metered into the high-pressure water jet to drastically increase cutting performance in hard-to-machine or thick materials. The particle size directly affects surface quality.

A device for precisely metering hard particles into the water jet. The amount of particles affects the removal rate and surface finish during cutting.

The abrasive dosing rate indicates how much abrasive is fed into the water jet per minute. An optimal dosing rate increases cutting performance and extends tool life.

The precise control of garnet feed into the water jet during high-speed cutting. Important for efficiency and results.

The shape, edges, and hardness of the particles in waterjet cutting. Sharp particles improve cut edges and erosion performance.

Abrasive nozzle: carbide or sapphire orifice that accelerates and focuses the water-abrasive mixture. Enhances cutting performance.

The maximum material thickness that can be separated with a specific abrasive water jet at a given feed rate without becoming unemulsified. It scales with pressure and particle concentration.

The pull-off test checks the adhesive strength of coatings or overlays on a material. A defined force is applied perpendicular to the surface to separate the material.

A movable, pipe- or hood-shaped component of an extraction system for flexible guidance of the capture hood close to the welding point. Articulated designs allow smooth positioning.

Movable capture element for welding smoke that intercepts glowing particles before they enter the piping system or filter through mechanical deflection. This minimizes the risk of fire in the filtration system.

A fume extraction welding tent is a mobile, enclosed system for capturing contaminants during repair work outdoors or in large halls.

The deposition rate indicates how much filler material is introduced into the weld pool per unit time. It affects the economy and quality of the weld.

Hardening sensitivity describes how much the mechanical properties of a steel are affected by slow cooling.

Rapid cooling of a heated component in a medium like water, oil, or gas to increase hardness through microstructural transformation.

Quench rate is the thermal gradient during cooling from the austenitizing temperature. It must exceed the critical cooling rate to avoid undesirable intermediate structures.

The residual stress distribution generated within the component due to non-uniform cooling rates and martensitic transformations. Surface compressive stresses significantly enhance dynamic fatigue strength.

Quench intensity indicates how quickly a cooling medium removes heat. It influences the structure and mechanical properties of the weld metal.

The quench intensity control regulates the heat transfer coefficient of the quenching medium to maintain the hardened depth precisely and avoid cracks.

A quenching medium is a coolant that increases the heat dissipation rate at the workpiece surface, thus preventing structural hardening.

Quenching media are liquid or gaseous media that remove heat quickly and prevent cold cracking. They improve weld strength and reduce porosity.

Quenching oil aging resistance: The oil remains stable under heat and oxidation, ensuring consistent cooling during welding.

Quench cracking is a separating structural failure caused by extreme thermal stresses and martensite formation during cooling.

Quenching severity is a characteristic value that measures the heat transfer capability of a quenching medium and influences the cooling rate at the workpiece surface.

The time-dependent temperature decrease of a workpiece in the quenchant, divided into vapor blanket, boiling, and convection stages. Precise tuning prevents unacceptable hardening defects or cracking.

An absolute probe is an eddy current sensor with a single active coil that measures absolute conductivity or geometric changes against an internal reference standard.

An absolute probe is an eddy current probe with a single active coil that detects absolute changes in material properties or geometries.

The absolute eddy current probe measures the electromagnetic field of a test part with a single measuring coil and outputs absolute values for conductivity or coating thickness. It responds to global field changes.

An absolute eddy current probe measures the absolute value of the magnetic flux through a measuring coil to determine material properties and material changes.

AC balance control adjusts the ratio of positive and negative phases during AC TIG welding of aluminum. It ensures a balance between oxide layer cleaning and penetration into the workpiece, improving weld quality.

A needle-like ferrite microstructure that preferentially nucleates on microscopic inclusions in weld metal. It significantly improves the low-temperature toughness of welds.

The cathodic removal of the high-melting oxide layer on aluminum achieved during the positive half-cycle in AC TIG welding.

Controls current, voltage, or wire feed dynamically during welding to prevent burn-through with changing root gap geometry and ensure consistent root penetration.

Adaptive process control adjusts welding parameters such as amperage or wire feed speed during the process to changing root gap dimensions to ensure consistent penetration conditions.

Adaptive robotic path control adjusts the robot's movement in real time to compensate for thermal distortion effects on the weld. This ensures uniform weld quality regardless of varying root gaps.

Voltage and amperage during welding are continuously adjusted to changing root gaps or heat conditions to prevent burn-through and lack of penetration.

A control system that adjusts current, voltage, or wire feed speed during welding to ensure consistent weld quality with varying gap sizes.

Automatic adjustment of the weaving width and frequency of the welding torch to a changing groove width. Ensures complete sidewall fusion.

Additive surface roughness modification improves surface roughness through microscopic processes to facilitate the sliding of weld materials and reduce porosity. This results in stronger welds.

Additively manufactured lattice structures are periodic, porous cellular geometries with high specific stiffness and low mass. They are produced by additive manufacturing processes such as SLS or SLA.