Detection of corrosion resistance of metallic materials
Tianjin Rong Da Testing Co., Ltd. contact: Wang Jingfu
Cell phone: 13102238283 QQ:3144667033
Telephone: 022-23892103
A standard metal test piece for corrosion testing is suspended in a monitoring test vessel or in the field of a heat exchanger or a test pipe. To monitor or evaluate the corrosion of the cooling water system. The pretreatment and after weighing the metal specimen placement test system for a period of time (such as 30 ~ 90 days), and then remove the observation of corrosion, cleaning and weighing, determination of metal corrosion rate (in mil / year, 1mpy=0.0254mm/a), the type of corrosion and pitting depth etc..
Metal hanging slice data in addition to corrosive effects, and hanging surface treatment, location, exposure time and sample metallurgy etc..
The corrosion types are divided into: galvanic corrosion; crevice corrosion; pitting corrosion; intergranular corrosion; delamination corrosion (selective etching); stress corrosion; interference in some special trace elements, when necessary to do further research in laboratory.
Used in the field to study the corrosion of the operation of the media, the following one to PTA production equipment as an example:
1, according to the purpose of choice of materials. If the device is on the corrosion resistance of the device and should choose the same material, if the material is selected, can choose according to need, such as 300 series alloy, Ti alloy, Ni alloy, super stainless steel etc..
2, sample processing. If the conditions should be in accordance with the relevant standards of sample processing, otherwise can according to the needs of processing, such as 30*50*2 can sample should be drilled for hanging; hanging sample before a proper pre-treatment, marking (multispecimen words), surface degreasing, acid washing, grinding, weighing etc. as a general, parallel 3-5.
3, the placement of samples. Choose a suitable location, choose according to erosion position is relatively static position; fixed specimens, samples were fixed in the corrosive environment, need to pay attention to the best suspension connecting wire is insulated, or is the same with the hanging piece of material.
4, the sample is taken out to deal with. After hanging for a period of time, the sample is removed, the first to remove the surface corrosion products, different materials have different methods. And then dry, weighing!
5, calculate the average corrosion rate. Two times the weight of the difference by the suspension time, you can get the corrosion rate