介绍
Low Alloy steel Structural Steel GB 1591–88
Low-alloy structural steel refers to the alloy structural steel with C content not exceeding 0.20% and the total amount of alloying elements not more than 5%. Generally, the strength level of low alloy structural steel is low, and its impact toughness and welding performance are better than that of ordinary carbon structural steel. GB 1591-88 is a Chinese national standard for low alloy high strength structural steel. It is mainly used for 30Mn2㎏, 30Mn2Si㎏, 12MnCu、25MnCu㎏ five series.
GB 1591-88 is a low-alloy structural steel developed to use high-strength steel and to meet the needs of the Chinese economy that cannot be replaced by high-quality foreign steel. Among them, 30Mn2、30Mn2Si㎏ are mainly used for the manufacture of clevis bolts and other mechanical parts. The steel of these two series has experienced thermomechanical rolling, resulting in higher yield strength and quality stability of the steel. After being cold-drawn or black drawn, the surface has a slightly smooth matte surface, which improves the oxidation resistance and wear resistance of the product. 12MnCu、25MnCu㎏ use thermomechanical rolling to improve the toughness of the produced steel. The cold drawn process adds a small amount of Cu elements to increase the plastic formation and fatigue performance of the steel.
Low alloy structural steels such as GB 1591-88 are widely used in engineering structures, ships, bridges and vehicles, machinery and other structural parts. The strength and toughness of low-alloy structural steels are much higher than those of ordinary carbon structural steels. Low-alloy structural steels not only have high strength but also have corrosion resistance, shock absorption, heat, and good gas and liquid sealing performance.
The production process of GB 1591-88 is complex and requires many precision machining and testing processes. The smelting process conditions the molten steel, and then the steel is subjected to thermomechanical rolling, pickling or black drawing, surface treatment (annealing, drawing, etc.), and then cut into the material to be used. The product machinery and performance are tested through a variety of different instruments and tests.
In conclusion, GB 1591-88 is a low-alloy structural steel with excellent properties, mainly used in engineering structures, ships, bridges and other structures. It is a kind of high-strength steel with excellent performance, which brings good benefits to the development of the national economy.
