Thirteen years

1. How to make the spring material

1. Grinding

(1) The process of refining iron ore into iron in a furnace (blast furnace) is called grinding ore. The outside of the furnace is a steel plate lined with refractory bricks. A blast furnace with a height of 20-30m and a diameter of 6-8m is called a blast furnace (a large-scale blast furnace with a daily output of more than 10,000 tons of iron grinding has a diameter of 13-14m and a furnace height greater than 100m). During smelting and ball milling, put iron ore, coke, limestone and other materials into the upper part of the blast furnace. The air heated by the hot blast furnace is blown into the lower tuyere of the blast furnace, and the coke in the furnace is burned to produce 1500. At high temperatures, the furnace gas that produces carbon monoxide (CO) rises from the furnace, and carbon monoxide reduces iron ore; the ground iron flows out of the grinding ore outlet under the furnace, and is temporarily stored in a mixed grinding furnace and transported to the steelmaking workshop. Or through the ladle melt ball mill, pour into the mold in the shape of pig trough.

2. Steelmaking

(1) The iron content of blast furnace smelting has high carbon content (C content greater than 3%), contains impurities such as silicon (SI), phosphorus (P), and sulfur (s), and the product is hard and brittle. This process is called steelmaking. In addition to grinding iron and scrap steel, the steel-making raw materials also include degreased flux, quicklime, fluorite, deoxidized alloy iron, etc., to improve the quality of steel. There are three steelmaking methods: converter, electric furnace and flat furnace. Different steel-making furnaces use different raw materials. The converter is used for melting and grinding, the electric furnace is mainly used for waste, and the open furnace is used for grinding and waste.

3. Steel making process

(1) The electric furnace steel-making process of the Dongguan Mechanical Spring Factory is a pot type, consisting of a furnace cover, a furnace wall and a furnace bed. The outer side is a thick iron plate, the inner side has a cooling water pipe, the hearth is made of refractory bricks and refractory materials, the furnace body can be tilted forward and backward, the center of the furnace cover is vertically inserted into the electrode, and the electrode can be adjusted automatically. The waste material is decomposed into high-quality steel products. There are two types of electric furnaces: DC furnace and AC furnace. One electrode is used for the DC furnace, and three electrodes are used for the AC furnace. Therefore, the unit consumption of the DC furnace electrode is low, the dissolution heat efficiency is good, and the noise is low.

(2) Converter steelmaking method: The converter mainly uses molten ore as raw material, the refining time is short, almost no fuel, and the cost can be reduced. The molten ore dissolved in the blast furnace enters the converter and blows high-pressure oxygen. High-purity steel can be refined by oxidizing and burning carbon and other impurities in grinding iron. There are three ways to blow oxygen: top blowing, bottom blowing and top bottom blowing.

4. Open furnace steelmaking process

(1) The open hearth furnace is a flat bottom reverberatory furnace. It adds grinding iron, scrap steel and limestone, heats and dissolves with fuel, and oxidizes carbon (c) and silicon (SI) phosphorus (P) in the grinding iron with oxygen or iron oxide. After refining, ferrosilicon, ferromanganese and aluminum are added to remove oxygen and nitrogen in the molten steel. It takes a long time to make steel. In recent years, this method has gradually disappeared, replaced by a converter. The molten steel cannot be rolled directly, and it must be made into semi-finished products such as flat steel blanks, outline blanks, small steel blanks by continuous casting. Continuous casting equipment has three forms: vertical, curved and horizontal. The equipment includes steel trough, copper mold, cooling device, straightener, wire drawing machine and cutting device. The molten steel flows out of the ladle, after cooling, it is heated for rolling. The method of direct rolling with unequal cooling after continuous casting is adopted to save energy and reduce consumption.