Manufacturing method of ultralow-temperature-impact resistant steel for high-intensity bolt of wind turbine generator set

A technology of high-strength bolts and manufacturing methods, applied in the field of steelmaking, can solve problems such as difficulty in impact work, stability assurance, and confusion, and achieve the effects of improving density and composition segregation, improving low-temperature ductile-brittle transition temperature, and promoting fine dispersion

Active Publication Date: 2017-10-27
山东寿光巨能特钢有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] At present, the market prospect of 42CrNi2Mo steel is good, but the production technology of this steel is very difficult, and the production of large-scale steel is even more difficult, which has long confused the steel manufacturers of high-strength bolts for wind power.
The technical bottleneck is manifested in two aspects: one is that the impact energy of large-scale steel at -101°C is difficult to guarantee stably; the other is that the steel contains high Ni and Cr elements, which makes it difficult to remove phosphorus from the rough rolling billet, resulting in The steel surface quality problems are prominent

Method used

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  • Manufacturing method of ultralow-temperature-impact resistant steel for high-intensity bolt of wind turbine generator set
  • Manufacturing method of ultralow-temperature-impact resistant steel for high-intensity bolt of wind turbine generator set

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Effect test

Embodiment 1

[0032] A method for manufacturing steel for ultra-low temperature impact-resistant wind power high-strength bolts, comprising the following steps:

[0033] Primary smelting of basic converter with top-bottom double blowing: the converter uses 72 tons of high-quality molten iron as the main raw material and 5 tons of pig iron to form the main raw material for steelmaking. Dephosphorization, terminal control (C+Mn) content wt is 0.18%, tapping P content wt is 0.010%; Add SiCaBaAl1.0kg / t steel, steel core aluminum 2.0kg / t steel deoxidation when tapping 15t, ferroalloy ( Ferroalloy materials include ferrosilicon manganese, ferrochrome, nickel plate and ferromolybdenum; among them, 2 / 3 of the nickel plate is added in the primary smelting furnace, 1 / 3 of the amount is added during the tapping process, and the nickel plate is kept at 650°C. hydrogen expansion annealing for 4.5 hours), recarburizer, slag material (slag material including 300kg / furnace lime, 500kg / furnace pre-melting r...

Embodiment 2

[0043] A method for manufacturing steel for ultra-low temperature impact-resistant wind power high-strength bolts, comprising the following steps:

[0044] Primary smelting of basic converter with top-bottom combined blowing: the converter uses 72 tons of high-quality molten iron as the main raw material and 8 tons of pig iron as the main raw material for steelmaking. The hot charging ratio of molten iron reaches 80%. The "double slag" method is adopted in the blowing process Dephosphorization, terminal control (C+Mn) content wt is 0.2%, tapping P content wt is 0.009%; when tapping 20t, add SiCaBaAl1.0kg / t steel, steel core aluminum 2.0kg / t steel deoxidation, ferroalloy ( Ferroalloy materials include ferrosilicon manganese, ferrochromium, nickel plate and ferromolybdenum; among them, 2 / 3 of the nickel plate is added in the primary smelting furnace, and 1 / 3 of the amount is added during the tapping process, and the nickel plate is kept at 750°C. hydrogen expansion annealing for...

Embodiment 3

[0054] A method for manufacturing steel for ultra-low temperature impact-resistant wind power high-strength bolts, comprising the following steps:

[0055] Primary smelting of alkaline converter with top-bottom combined blowing: the converter uses 72t of high-quality molten iron as the main raw material and 7t of pig iron as the main raw material for steelmaking. The hot charging ratio of molten iron reaches 80%. During the blowing process, lime, dolomite, Adding amount of ore, etc., using "double slag" method for dephosphorization, end point control (C+Mn) content wt is 0.18%, tapping P content wt is 0.010%; add SiCaBaAl 1.0kg / t steel and steel core when tapping 18t Aluminum 2.0kg / t steel deoxidation, ferroalloy material (ferroalloy material includes ferrosilicon manganese, ferrochromium, nickel plate and ferromolybdenum; among them, 2 / 3 of the quantity of nickel plate is added in the primary smelting furnace, and 1 / 3 of the quantity is added in the tapping process and the ni...

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Abstract

A manufacturing method of ultralow-temperature-impact resistant steel for a high-intensity bolt of a wind turbine generator set comprises the following steps: primarily melting by a top-bottom combined blowing basic converter; refining by an LF refining furnace; degassing by a VD vacuum furnace; continuously casting by a round billet arc-shaped continuous casting machine; heating rolled steel; dephosphorizing and oxidizing iron scales; rolling; and drawing into a pit and slowly cooling. According to the method, the development and design are on the basis of three aspects, namely, high toughness, delayed fracture resistance and cold deformability; after the whole round steel is thermally processed, the performance indexes reach that Rm is not less than 950Mpa, Re is not less than 830Mpa, A is not less than 20%, Z is not less than 60%, and KV2 (-101 DEG C) is not less than 30J.

Description

technical field [0001] The invention relates to the technical field of steelmaking, in particular to a method for manufacturing ultra-low temperature shock-resistant wind power high-strength bolt steel. Background technique [0002] L43 grade bolts are widely used in high-strength bolts in large-scale wind turbines. In order to adapt to the independent design and development of higher-power wind turbines, they can ensure the reliability of the entire wind turbine operation and meet the needs of wind power manufacturers. As the foundation of wind turbines, fasteners bear additional axial tensile (alternating) loads and transverse shear (alternating) loads together with wind turbines in the connection of the main engine, blades, towers and gearboxes Or the effect of the bending load compounded therefrom, and sometimes the impact load and long-term field service and harsh environmental conditions. It needs to have good cold pier performance, high tensile strength and plasticit...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/02C22C38/04C22C38/44C22C38/06C22C33/04C21C5/35C21C7/06C21C7/10C21D8/06
CPCC21C5/35C21C7/06C21C7/10C21D8/065C22C33/04C22C38/02C22C38/04C22C38/06C22C38/44Y02P10/20
Inventor 张明荣刘发友朱卫东尚明桑培宇王德龙刘勇丁秀中王超刘世义张艳福张永安杨子江
Owner 山东寿光巨能特钢有限公司
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