Galvanized steel sheet tensile strength testing machine, galvanized steel sheet hardness test method, galvanized steel sheet bending strength testing machine
Hardness testing of tinplate
1. What is tinplate:
Tinplate is an iron sheet with a layer of tin plated on the surface, it is not easy to rust, also called tin plated iron. It is made by immersing an iron piece in molten tin. Tin is a metal that is less active than iron. It is neither oxidized by air nor reacted with water, so it has quite strong corrosion resistance. A thin layer of tin plated on the iron sheet can provide good protection. However, once the plating layer is damaged and electrochemical corrosion occurs, because iron is more active than tin, iron will be used as the negative electrode of the galvanic battery and will be lost due to oxidation reaction. The presence of tin will accelerate the corrosion rate of iron, so tinplate is different from white iron. Only when the coating is intact can it protect the iron.
Tinplate was first produced in Bohemia (in today’s Czech Republic and Slovakia). The area has been rich in metal since ancient times, with advanced technology, and knows how to use hydraulic power for machine manufacturing. Tinplate has been produced since the 14th century. For a long period of time, this place has been the main producing area of tinplate in the world. At that time, tinplate was mainly used to make tableware and drinking utensils.
In the 17th century, Britain, France, and Sweden all hoped to establish their own tinplate industries, but they have not been developed due to the large capital needs. It was not until 1811 that Brian Donkin and John Hall started tinplate canned food that tinplate manufacturing developed on a large scale. Today, the world produces about 250,000 tons of tin annually, and more than one third is used to make tinplate, most of which is used in the canned food industry.
2. Hardness test of tinplate:
In the past, the hardness test of tinplate mostly used the desktop surface Rockwell hardness tester, and the ordinary steel flat anvil was used to test the HR30T hardness.
In recent years, since the national standard GB/T2520-2000 for tinplate has adopted the internationally accepted HR30Tm hardness representation method, diamond anvils have been used in China to test the HR30Tm hardness value of tinplate.
However, testing the hardness of HR30Tm requires a diamond anvil, and the domestic Rockwell hardness tester rarely has such accessories to buy. Since suitable diamond anvils are difficult to buy, desktop surface hardness testers are more expensive. Therefore, the HR30Tm hardness representation method is not widely used in the domestic tinplate industry. Especially in terms of tinplate manufacturers, although people always realize that the hardness of tinplate is very important, it has to do with the quality of processed products, production efficiency and corporate benefits. However, most companies have not re-examined the hardness of the purchased tinplate.
Now the situation is different. The PHR series portable surface Rockwell hardness tester is only one percent of the weight of the desktop computer, and the price is only half of the desktop computer. The accuracy is the same as that of the desktop computer. They all meet the national standards on Rockwell hardness testing. The provisions of GB/T 230.1-2004. As an option, Shenyang Baote Instrument Co., Ltd. can also provide a diamond point anvil for testing the hardness of HR30Tm. Its price is only one-fifth of the domestic similar products.
To test the hardness of tinplate, you can use the PHR-1S surface Rockwell hardness tester. Its weight is only 0.7kg. It can test strip materials with a thickness of 0.05~25mm, test the inner wall hardness of pipes with an inner diameter of 26mm or more, and test those with an inner diameter of 30mm or more. Hardness of the outer wall of the pipe. Equipped with a diamond anvil, the HR30Tm hardness of tinplate can be tested. This instrument can be conveniently taken to the production site, sales site and material warehouse to use. It can be used for the online quality control of tinplate production plants, it can also be used for the material re-inspection of tinplate use factories, and it can also be taken to the steel market to purchase materials. If equipped with an optional support base, it can also be placed on a platform (such as a desk) for accurate testing.
The PHR-1S surface Rockwell hardness tester is very suitable for testing the hardness of tinplate. Its adoption will definitely bring obvious benefits to tinplate manufacturers and users.