Common Stainless Steel Smelting, Forging, and Rolling Issues

Shrinkage Cavities

Shrinkage cavities form in the steel mold when molten steel shrinks.

Transverse Cracks

Transverse cracks occur on the surface of steel ingots, usually shallow and removable by fine grinding.

Longitudinal Cracks

Longitudinal cracks appear on the upper part and corners of steel ingots. Upper cracks are deep and challenging to remove by grinding.

Scarring

Metal splashes or tumors adhere to the surface of steel ingots, mainly in the lower part.

Double Skin

Irregular dark coloring and looseness around the edge of low-magnification test pieces indicate duplication, caused by oxide inclusions.

Surface Inclusions

Visible non-subtractive inclusions embedded in the steel ingot’s surface.

Surface Pores

Tiny holes exposed on the steel ingot’s surface, generally shallow and removable by finishing.

Bursting

Cracking occurs due to extreme cold on the steel ingot’s surface, often accompanied by a sound.

Rising

Irregular convexity at the head of the steel ingot.

Reticulation

Mesh-like protrusions on the steel ingot’s surface.

Pockets

Pits on the steel ingot’s surface.

Double Pouring

Obvious reconnection marks around the steel ingot’s surface.

Flash

Metal flakes at the head or tail of the steel ingot, perpendicular to its surface.

Flying Fins

Thin sheets formed on the steel ingot’s surface, perpendicular to its surface.

Bubbles

Defects caused by degassing and deoxidation during steel ingot production, divided into subcutaneous and internal bubbles. (Prevention methods include ensuring good steel oxidation, boiling, reduction, and deoxidation, keeping all steel contact materials dry, and maintaining clean molds and even oil distribution.)

White Spots

Fine cracks caused by hydrogen, appearing as irregular jagged cracks on low-magnification samples and round or elliptical silver bright spots on longitudinal samples.