The Difference Between Gelat And Cold Zahang
Hot-rolled and cold-rolled as the most popular in the market two kinds of steel processing methods, by the vast number of steel manufacturers use, the two steel processing technology in the end what is the difference?
I. Cold rolling
Cold rolling is to refer to cold drawing, Leng, cold, etc. in the room temperature, steel or steel strip processing into a variety of shapes, the market is very popular cold draw flat steel, cold drawn flat steel manufacturers are also very many.
Advantages: Cold rolling can make the product rapid prototyping, high output, and the process will not damage the coating, can be made into a variety of cross-section form, to adapt to the use of conditions; cold-rolled steel can produce a large plastic deformation, thereby improving the yield point of steel.
Disadvantage: Although there is no thermal plasticity in the molding process, but residual stress is still in the section, this will affect the whole and local buckling of steel. Cold rolled steel is generally an opening section, so that the free torsion of the section is low, when the external force is prone to torsion, and under pressure will be prone to bending buckling, the steel itself is poor torsional performance; After the cold-rolled steel is formed, there is no thickening in the joint of the plate, so the local tolerance of the steel is poor.
II. Hot rolling
Advantages: The steel can be deeply damaged, the defect of microstructure is eliminated, the microstructure of the steel is compacted, and the mechanical properties are improved. This kind of improvement mainly manifests in along the making direction, the steel in certain degree will not be all the same body. The cracks and bubbles formed during pouring are also eliminated at high temperatures.
Disadvantage: After hot-rolled, steel internal non-metallic inclusions will be squeezed into thin slices, leading to the phenomenon of delamination, delamination may make steel in the weld shrinkage when the tear occurs; the residual stress is caused by the uneven cold, which causes the deformation of the steel, reduces the stability, and reduces the fatigue resistance in some degree.
Third, hot-rolled and cold-rolled difference:
(1) The steel section of cold rolling allows local buckling, which can make full use of the buckling bearing capacity;
(2) The residual stress of hot-rolled flat steel and cold La Chang on the steel is different, so there is a great difference in the distribution of the section. The residual stress of cold drawing is mainly curved type, and hot rolling is mainly film type.
(3) The free torsion of hot-rolled section steel is higher than that of cold-drawn steel, so the torsional performance of hot-rolled steel is better than that of cold-rolled steel.