Low-temperature impact resistant 42CrMoVNb steel for wind-power variable propeller and yaw bearing ring

Abstract

The invention relates to a 42CrMoVNb steel, which can resist a low temperature impact and is used for the variable pitch wind turbine and the yaw bearing ring. The weight percentage for the components of the steel is as follows: C 0.42 to 0.45 percent, Si 0.15 to 0.30 percent, Mn 0.60 to 0.90 percent, Cr 0.90 to 1.20 percent, Mo 0.15 to 0.30 percent, Ni 0.35 to 0.60 percent, V 0.08 to 0.15 percent, Nb 0.03 to 0.06 percent, Cu less than or equal to 0.20 percent, Al less than or equal to 0.05 percent, S less than or equal to 0.015 percent, P less than or equal to 0.015 percent, As less than or equal to 0.015 percent, Sn less than or equal to 0.012 percent, : less than or equal to 20PPM, <H>: less than or equal to 2.0PPM and the rest are Fe and natural impurities. The impact resistant capability of the steel at a low temperature is improved by adding vanadium and niobium to the prior 42CrMoVNb steel. The upper limit value for the carbon content is adopted to help to reach the requirement of HRC 55 to 60 after the surface is quenched and backfired. During the steel smelting, Al, As and Sn are used for slag forming and degassing to increase the content. The Akv detected at minus 40 DEG C by three samples reaches 91J, 97J and 98J respectively, which is exceeds the required value of minus 45 DEG C and is 3.37 times of the standard value. After being commuted, the requirement that Akv is equal to 27J at minus 70 DEG C can also be satisfied. The invention sets a precedent for the development of a steel demanding for an Akv at a lower temperature and fills the domestic gap. The invention is applicable to bearing and mechanical components, in particular to variable pitch wind turbines and yaw bearings.

Description

[0001] (1) technical field: the present invention relates to a kind of low-temperature impact-resistant alloy structural steel. It belongs to alloy (C22C). It can be used for bearings and mechanical components, especially for pitch and yaw bearing rings of wind turbines. (two) background technology: [0002] As one of the renewable energy sources, wind power has the largest reserves and exploitable capacity in the world, and it has been included in the national energy development policy. Since the wind power sources are located in high mountains, plateaus, coasts and offshore areas, the temperature and environment vary greatly, and the wind turbines are installed on towers tens to hundreds of meters high. , wind power manufacturers put forward the following requirements: not to be replaced or overhauled within 20 years; resistant to wind and sand and saline-alkali climate; to meet the environmental requirements of ±45°C, [0003] The impact energy Akv≥27J at ℃. In my countr...

AI Technical Summary

Problems solved by technology

[0009] The 42CrMoVNb steel for wind power variable pitch and yaw bearing rings resistant to low temperature impact proposed by the present invention is to solve the problem that the existing alloy steel 42CrM cannot meet the yaw and pitch variable bearing ring materials proposed by wind power manufacturers at -45°C The problem of the requirement of impact energy Akv≥27J