Iso-Hardness Contour in Weld Metal
The iso-hardness line shows equal hardness values across the weld cross-section and helps identify embrittlement zones. It validates numerical simulations.
Physical-Chemical Mechanism of Action
The iso-hardness line visualizes the hardness distribution in a weld by lines of equal hardness values. These lines result from different cooling times and rates, which lead to different microstructures and hardnesses.
Metallurgical Relevance & Risks in Welding
The iso-hardness line indicates embrittlement zones where hardness is uneven. These can lead to cracks and deformation. Uneven hardness distribution can also impair toughness and load-bearing capacity of the weld.
Shop Practice & Instructions
To create an iso-hardness line, measure the weld with a hardness tester (e.g., Brinell or Rockwell tester) and plot the results graphically. If hardness values are uneven, check and optimize cooling times to achieve an even hardness distribution.