Q235 is a common carbon structural steel. The main components of Q235 include carbon, manganese, silicon, sulfur and phosphorus. Its carbon content is usually between 0.10% and 0.20%, and its manganese content is between 0.30% and 0.70%, while the sulfur and phosphorus content should be controlled at a low level to ensure the toughness and weldability of the steel.
In terms of physical properties, the yield strength of Q235 is usually around 235 megapascals (MPa), hence the name "Q235". Its tensile strength is generally between 370 and 500 MPa, and its elongation is above 20%. These properties enable Q235 to maintain good deformation capacity when subjected to loads, making it suitable for the manufacture of load-bearing components. The hardness of Q235 is relatively low, making it easy to process and form.

Q235 steel can be processed in a variety of ways, including hot rolling, cold rolling, forging, etc.

When the content of alloy elements in the steel is uneven or the distribution of alloy elements is uneven, it will affect the chemical composition of the steel. If the carbon content in the steel is uneven or the distribution of other alloy elements is unbalanced, it will cause cracking at the end of the round steel.

The causes of round steel cracks may include uneven heating temperature, too fast heating speed, and low rolling temperature.