Solidification cracking in stainless steel can be caused by the presence of which impurity?

Solidification cracking in stainless steel is primarily influenced by the presence of certain impurities, among which sulfur is a significant factor. When sulfur is present in steel, it can form low-melting-point sulfides during the solidification process. These sulfides may lead to localized areas of weakness within the solidifying metal, making it more susceptible to cracking as the material cools and contracts.

In the case of stainless steel, the desirable properties that the alloy achieves can be compromised by sulfide inclusions, which can adversely affect the segregation of alloying elements during solidification. This contributes to the formation of cracks, particularly in joints or areas of high restraint where stress concentrations are more pronounced.

While the other impurities listed—chlorine, silicon, and fluorine—can also affect metal properties, they are not typically associated with solidification cracking in the same manner that sulfur is. Chlorine, for instance, can lead to issues such as corrosion or affect surface quality, but it does not have the same impactful role on solidification behavior. Silicon can actually be beneficial to fluidity and reducing oxidation but, in excess, may promote hot cracking under different conditions. Fluorine is rarely an incidental impurity in steels and does not have the same relationship with