Abstract
This paper evaluates the cold-rolled ribbed steel bar mechanical performance, process performance and surface quality by comparing with GB13788-2000 and other standards. Cold-rolled ribbed steel bar is widely used in reinforced concrete and other building structures. In this paper, a series of experiments are conducted to evaluate the mechanical performance, process performance, and surface quality of cold-rolled ribbed steel bar. The results show that the yield strength, tensile strength, elongation and carbon content of cold rolled ribbed steel bar meet GB 13788-2000 standard requirements, indicating that the cold-rolled ribbed steel bar is of excellent quality. The above results and analysis show that the cold-rolled ribbed steel bar has good mechanical performance, process performance and surface quality, and meets the requirements of GB 13788-2000.
Keywords: Cold-rolled ribbed steel bar, mechanical performance, process performance, surface quality
1. Introduction
Cold-rolled ribbed steel bar is a kind of steel bar product with ribs on the surface. It is mainly used as the reinforced steel bar in reinforcing concrete and other building structures. Many construction projects need to use it, such as bridge and wharf, high-rise buildings, tunnels and so on. It not only determines the strength and bearing capacity of the structure, but also affects the shape and appearance quality of the structure.
The cold-rolled ribbed steel bar has a poor surface quality due to the ribs, so the surface quality is also an important assessment standard for its quality. The use of cold-rolled ribbed steel bar in China is mainly in accordance with GB13788-2000, which stipulates the surface quality of cold-rolled ribbed steel bar.
2. Experimental materials and methods
2.1 Experiment sample
A batch of cold-rolled ribbed steel bars produced by a large-scale steel plant are selected as the experimental samples, with a diameter of 16mm and a length of 3000mm.In order to assess its mechanical properties, surface quality, process performance and other performance indicators, a series of experiments were carried out.
2.2 Test equipment
Tensile testing machine, surface roughness tester and other necessary testing equipment used for material testing.
2.3 Test process
The test is divided into three parts: mechanical performance test, process performance test and surface quality test.
(1) Mechanical performance test. Tensile testing machine to test the yield strength, tensile strength and elongation of cold-rolled ribbed steel bar;
(2) Process performance test. The deflection was measured by curvature measurement instrument to test its straightness;
(3) Surface quality test. Contact roughness tester and optical microscope are used to measure the surface roughness and microscopic structure of cold-rolled ribbed steel bar.
3. Test results and discussion
3.1 Test results
The test results are shown in Table 1.
Table 1 Test results
Items Result Yield Strength (MPa) 325 Tensile Strength (MPa) 410 Elongation (%) 10.5 Straightness (mm/m) 2.2 Carbon Content (%) 0.41 Surface Roughness (Ra) 0.80
3.2 Discussion
The mechanical properties, process performance, and surface quality of cold rolled ribbed steel bar have been tested. In order to compare with GB13788-2000 standard requirements, the actual test results are listed in Table 2.
Table 2 Comparison of test results and GB13788-2000 standard requirements
Items Requirement Test Results Difference Yield Strength (MPa) ≥ 295 325 >30 Tensile Strength (MPa) ≥ 385 410 >25 Elongation (%) ≥ 8 10.5 >2.5 Straightness (mm/m) ≤ 4 2.2 <1.8 Carbon Content (%) ≤0.45 0.41 >0.04 Surface Roughness (Ra) ≤1 1 >0.2
It can be seen from Table 2 that the yield strength, tensile strength, elongation and carbon content of cold rolled ribbed steel bar meet the requirements of GB13788-2000 standard, and the surface roughness is slightly higher than the requirements, but still meets the standard requirements. The above results and analysis show that the cold rolled ribbed steel bar has excellent mechanical properties, process performance and surface quality, which meet the requirements of GB13788-2000.
4. Conclusion
Through the above experiment, it can be seen that the cold-rolled ribbed steel bar has excellent mechanical properties, process performance and surface quality, and meets the requirements of GB13788-2000. The quality of the product is in line with the national standard, which proves that the cold-rolled ribbed steel bar produced by this enterprise is of excellent quality.
