Surface quality:

The surface of steel bars for pressure processing shall not have visible cracks, scars, folds and inclusions. If the above defects should be cleared, the clearance depth shall not exceed the standard specified in the actual size of the steel bar. Clear width of not less than 5 times the depth. For steel bars with a nominal diameter or thickness greater than 140mm, The maximum clearance depth in the same screenshot should not be greater than 2. Allows small cracks, indentations, pits and small cracks with depths not greater than 0.2mm from the actual size tolerances.

Mechanical properties:

The longitudinal tensile properties of the blank made of the blank made of the test steel bars shall be in accordance with the provisions of GB/T 699-2015. If the supplier can ensure that the tensile properties of qualified, supplier can not be tested.
According to the requirements of the buyer, the longitudinal impact absorption energy of 25-50 and 25Mn-50Mn steel bars is determined by the heat treatment (quenching + tempering) blank GB/T, 699-2015. The nominal diameter less than 16mm steel and the nominal thickness less than 12mm steel, flat steel, no impact test.
The hardness of the steel bars used for the cutting of steel bars or cold drawing shall be in accordance with the provisions of GB/T 699-2015. The hardness of the heat treated steel, if the supplier can guarantee qualified, can not be tested. The hardness of steel bars after high temperature tempering and normalizing shall be determined by both parties.
According to the requirement, the tensile strength of 25-60 steel bar GB/T 699-2015 allows 20MPa lower than the specified value, but its elongation also increased 2% (absolute value).

With the agreement between the supplier and the buyer, and in the contract, the following steel bar can be supplied In special requirements:

A) the scope or relaxation of the Chinese composition of the grades listed in GB/T 699;
B) sulfur content range is controlled at 0.015%-0.035%;
C) oxygen content or other residual elements are required;
D) steel bars for hardenability requirements;
E) grain size inspection;
F) inspection of nonmetallic inclusions;
G) inspection of tower lines;
H) Ultrasonic testing;
I) other

Steelmaking Products