Laiwu steel thread steel trademark color blue and red Qu Qu
In the purchase of rebar, first of all, from the surface quality, the surface of normal steel without cracks, scarring and folding. The surface shall have a bump, but shall not exceed the height of the cross rib, and shall also have a quality grade mark on the surface of the steel bar. Inferior thread steel due to rolling with adobe, its surface quality is poor, often with burrs, burrs, cracks, scarring, some distortions obvious, end of irregular, and even cracks. At the same time, some small mill due to heating temperature and rolling speed is not enough, the surface color is red, uneven color. Second, from the appearance of size, you can use vernier caliper to measure whether the actual size is consistent with the marked size (general thread steel rolled with specifications), if there is a difference in the standard deviation (such as? 16 the standard diameter of the thread steel is 15.4 + 0.4mm, while the quality of the false thread steel is mostly about 13mm. Third, regular steel at the factory, mostly large bundles of packaging, bundles of steel are linked with the physical corresponding metal signs, indicating the factory name, steel number, batch number, specifications and inspection code. But shoddy steel due to poor production conditions, no large hoisting equipment, mostly small (about ten strapping) package or in bulk, no metal signs, no guarantee of quality.
The current steel market shoddy (commonly known as hot rolled ribbed steel rebar) unqualified factors are mainly: 1, the actual size than the nominal size is small, the actual weight of dealers through purchase, the amount of metal delivery weight theory earn profits. 2, the intensity is low. 3, the chemical composition unqualified rate is high. The main reason is that the raw material of the small rolling mill is not qualified, and the steel billet is rolled by soil.
It is suggested that the users must obtain the certificate of quality of steel when they buy the thread steel, and check and accept it. For quality problems, the quality inspection and inspection can be carried out at the professional inspection organization.
