Alloy constructional steel for large-scale wind power principal axis

Abstract

The invention relates to structural alloy steel used on a large-scale wind-power main shaft. The structural alloy steel mainly comprises the chemical compositions by weight percentage as follows: C is 0.38 to 0.45 percent, Si is 0.17 to 0.37 percent, Mn is 0.50 to 0.80 percent, Cr is 0.90 to 1.20 percent, Ni is 0.30 percent, Mo is 0.15 to 0.25 percent, P is less than or equals to 0.035 percent, S is less than or equals to 0.035 percent, and other weight percentage is composed of Fe and ineluctable impurities. Ni alloying element, which is used for improving the low-temperature impact property of the steel and is 0.30 percent, is added in 42CrMo structural alloy steel, so that the special requirement of ultralow temperature (that is lower than minus 40 DEG C) performance of the wind-power main shaft can be satisfied on the premise that the mechanical property of the 42CrMo structural alloy steel is not changed.

Description

technical field [0001] The invention relates to an alloy structural steel for a large-scale wind power main shaft. It belongs to the field of wind power technology. Background technique [0002] The large-scale wind power main shaft is the most critical component in the wind power industry. With the expansion of wind power installation areas, especially in the alpine areas with rich wind energy resources, such as my country's "Three North" regions, it proposes ultra-low temperature ( -40℃) special requirements for impact toughness. [0003] 35CrMo or 42CrMo alloy structural steel is mostly used for the main shaft of the generator, which is the key component of the turbogenerator. This is not only because of their high strength, high toughness, high hardenability, and small deformation during quenching, but also because of their high creep strength at high temperatures. And durable strength, especially it can work under the high temperature condition of 500 ℃ for a long time...

AI Technical Summary

Problems solved by technology

[0005] It is also recommended to replace 34 CrNiMo6 with alloy structural steel 42CrMo6 in China. 42CrMo does not contain Ni element. Compared with 34 CrNiMo6, its chemical composition is slightly higher in carbon, manganese and chromium (see attached table 1), and its strength performance is slightly higher. The performance is equivalent (see attached table 3), but 42CrMo materials are not tested for low-temperature performance in China. In recent years, due to the expansion of its use, some projects have increased low-temperature (-20°C) impact toughness inspection requirements (see attached table 3), but 42CrMo cannot fully meet the requirements of 34CrNiMo6 in terms of ultra-low temperature (-40°C) performance. This puts forward special requirements to meet the ultra-low temperature performance of large-scale wind power main shafts. It has become an urgent requirement to improve the alloy structural steel 42CrMo!

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