1、牌号和化学成分:镀锌钢管用钢的牌号和化学成分应符合GB 3092所规定的黑管用钢的牌号和化学成分。2、制造方法:黑管的制造方法（炉焊或电焊）由制造厂选择。镀锌采用热浸镀锌法。3、螺纹及管接头:3.1 带螺纹交货的镀锌钢管，螺纹应在镀锌后车制。螺纹应符合YB 822的规定。3.2 钢制管接头应符合YB 238的规定；可锻铸铁管接头应符合YB 230的规定。4、力学性能 钢管镀锌前的力学性能应符合GB 3092的规定。
是将钢、不锈钢、铸铁等金属浸入熔融液态金属或合金中获得镀层的一种工艺技术。热镀锌是当今世界上应用广泛、性能价格比优的钢材表面处理方法。热镀锌产品对钢铁的减蚀延寿、节能节材起着不可估量和不可替代的作用，同时镀层钢材也是扶植和优先发展的高附加值短线产品。 热镀锌加工介绍上料工应检查原料情况：1、钢管的外表面不得粘有油污（特别是沥青油调合漆等油污），否则会造成大批不合格品。 2、钢管在生产后一定要矫直，消除钢管的内应力。3、钢管外表面出现凹凸不平的腐蚀不能镀锌，否则将浪费大量盐酸。4、钢管在运输过程中不能出现人为弯管。5、用于热镀锌的钢管，不允许把标识物贴在钢管的内、外壁上，以免造成漏镀。
The forced cooling on the vertical outgoing frame is 300-400mm above the zinc level of the steel wire. In this way, the vertical extraction method is better than the inclined extraction method in hot galvanizing.
The hot-dip process includes three parts: surface pretreatment, hot-dip and post-treatment. According to different surface pretreatment methods, it can be divided into solvent method and protective gas reduction method. Among them, the hydrogen reduction method is mostly used for continuous hot-dip coating of strip steel, and the typical Sendzimir method and American steel joint method belong to this kind of process.
There are also great differences in the adhesion between the cold galvanized steel pipe and the hot galvanized steel pipe. The adhesion of the cold galvanized steel pipe is much worse than that of the hot galvanized steel pipe. Because there is a very thin zinc layer between the steel pipe base and the zinc layer of the cold galvanized steel pipe, and it is still attached to the steel pipe base briefly, so the cold galvanized steel pipe is very simple to fall.
Hangzhou galvanized handrail manufacturer
1. Brand and chemical composition: the brand and chemical composition of galvanized steel pipe shall conform to the brand and chemical composition of black pipe steel specified in GB 3092. 2. Manufacturing method: the manufacturing method of black tube (furnace welding or electric welding) shall be selected by the manufacturer. Hot dip galvanizing is adopted for galvanizing. 3. Thread and pipe joint: 3.1 galvanized steel pipe delivered with thread shall be machined after galvanizing. Threads shall be in accordance with Yb 822. 3.2 steel pipe joint shall conform to Yb 238; malleable cast iron pipe joint shall conform to Yb 230. 4. Mechanical properties the mechanical properties of steel pipe before galvanizing shall comply with the provisions of GB 3092.
It is a kind of technology to dip steel, stainless steel, cast iron and other metals into molten metal or alloy to obtain coating. Hot-dip galvanizing is a widely used method of steel surface treatment in the world. Hot dip galvanizing products play an inestimable and irreplaceable role in reducing corrosion and prolonging life, saving energy and materials of iron and steel. At the same time, coated steel is also a short-term product with high added value, which is supported and developed preferentially. Introduction to hot galvanizing process: 1. The outer surface of steel pipe shall be free of oil stains (especially oil stains such as asphalt oil blending paint), otherwise a large number of unqualified products will be caused. 2. The steel pipe must be straightened after production to eliminate the internal stress of the steel pipe. 3. The uneven corrosion on the outer surface of the steel pipe cannot be galvanized, otherwise a large amount of hydrochloric acid will be wasted. 4. The steel pipe shall not be bent artificially during transportation. 5. For the steel pipe used for hot galvanizing, it is not allowed to stick the mark on the inner and outer walls of the steel pipe to avoid missing plating.
The more complex the behavior in industrial production, the single metal can not meet the multiple standards of industrial production. High temperature resistance and oxidation resistance have become the general requirements of industrial production, but only a small amount of precious metals can meet such high industrial requirements. For example, zinc used in hot-dip galvanizing has the characteristics of oxidation resistance. In order to control the cost and absorb the advantages of different metals, more and more alloy and gold plating industries are born.
It must be noted that in a hot zinc solution tank of about 450 ℃, steel parts will be immersed and lifted. Any feature that can help them to inject and discharge zinc will improve the quality and reduce the hot-dip zinc. For some steel members, the holes used for other purposes may meet the requirements of hot-dip zinc injection and zinc discharge, but other steel members may need to provide additional zinc injection and zinc discharge holes. In order to provide a comprehensive corrosion protection layer, hot zinc solution must be allowed to flow into each surface of the component.
Hangzhou hot dip galvanized steel guardrail manufacturer
Contact hazards when acid or alkali washing solution is prepared, skin damage may be caused by splashing of acid or strong alkali on the skin. Special attention should be paid to the harm of zinc chloride to the skin when preparing or adjusting the double salt solution of "zinc chloride + ammonium chloride" as the auxiliary plating solution. In terms of characteristics, zinc chloride itself is corrosive. It can burn skin and mucous membrane violently.
Galvanized steel is widely used in all walks of life. The advantage of using galvanized steel is to protect the internal steel structure by using the metal zinc which can form a dense oxide protective layer in the air. In the case of being welded and scratched, due to the existence of Zn Fe primary battery, the relatively active galvanized part can be used as a sacrificial anode, which can delay the corrosion of steel and has good corrosion resistance.