ADVANCES DUCTILITY TESTING FOR MODERN MATERIALS
 

What Is Ductility Testing?
Ductility testing measures a material's ability to undergo plastic deformation under tensile stress before fracture. As a specimen is loaded to failure, the resulting reduction in area and elongation at fracture are recorded — quantifying how much a material can deform before breaking and providing direct insight into cracking susceptibility under real processing conditions.

Unlike static mechanical testing, ductility is not a fixed material property. It is highly dependent on temperature, strain rate, and processing history — meaning ambient laboratory measurements often fail to predict behavior during continuous casting, welding, hot rolling, or additive manufacturing post-processing. A material that appears adequately ductile at room temperature may pass through a ductility trough at elevated temperature where cracking risk is severe. The Gleeble captures this behavior by performing tensile deformation under precisely controlled thermal cycles, producing on-heating and on-cooling ductility curves that map the full range of process-relevant conditions.

For steel producers, weld engineers, and alloy developers working with materials where cracking susceptibility determines product quality and process yield, this distinction is critical. The nil ductility temperature, the ductility recovery temperature, and the width of the brittle temperature range are properties that only emerge from thermally coupled testing — and the Gleeble has been the industry standard for this measurement for decades.

Pain Points We Solve
 

• Ambient ductility data that fails to predict hot cracking or casting defects — the Gleeble tests across the full thermal cycle your process imposes, including during solidification and phase transformation
• No clear process window for forming, straightening, or bending operations — the Gleeble maps ductility across temperature to identify safe and unsafe operating ranges
• Weld procedure qualification based on incomplete HAZ characterization — Gleeble hot ductility testing evaluates liquation cracking susceptibility with on-heating and on-cooling curves under controlled thermal profiles
• Alloy development slowed by trial-and-error composition screening — the Gleeble quantifies how individual alloying elements affect hot ductility from small laboratory specimens before committing to production heats
• Production defects with no clear root cause — the Gleeble replicates the exact thermal-mechanical history of a defective component to isolate contributing factors and validate corrective actions

Comprehensive Ductility Property Characterization

This dataset captures material ductility behavior across the full range of thermally and mechanically relevant conditions. Reduction in area and elongation at fracture quantify plastic deformation capacity as a function of temperature, strain rate, and thermal history — forming the basis of hot ductility curves used in process design. The nil ductility temperature (NDT) and ductility recovery temperature (DRT) define the brittle temperature range, enabling secondary cooling strategy development for continuous casting and straightening operations.

On-heating and on-cooling ductility curves distinguish between solidification-range cracking mechanisms and solid-state precipitation effects, informing both alloy design and welding procedure development. HAZ liquation cracking susceptibility assessment supports weld procedure qualification and preheat requirement definition. Microalloy carbonitride precipitation effects — including the detrimental influence of niobium, vanadium, and titanium on ductility trough depth and width — are quantified to guide composition optimization. Fracture morphology analysis, correlated with ductility measurements across temperature, identifies the transition between ductile intergranular and brittle intergranular failure modes for mechanistic understanding and material development.