Ito-Bessyo Cracking Parameter
The Wpeč value according to Ito-Bessyo is a parameter for estimating the cracking tendency of high-strength steels under the influence of diffusible hydrogen and chemical composition. It is used for low-alloy steels with low carbon content.
Physical-Chemical Mechanism of Action
The Wpeč value accounts for the diffusion of hydrogen into the metal and its effect on crack susceptibility. In low-alloy steels with low carbon content, hydrogen can impair strength and increase susceptibility to cracking.
Metallurgical Relevance & Welding Risks
A too high Wpeč value indicates increased susceptibility to cracking. If handled incorrectly during welding, such as too fast cooling or insufficient deoxidation, hydrogen diffusion can be intensified and the risk of cracking increases.
Workshop Practice & Instructions
When welding steels with a high Wpeč value, careful control of temperature gradients is essential. Use a long cooling time (t8/5 > 25 s) and ensure that the weld is properly built up. This reduces the risk of cracking and improves the toughness of the weld.