How long steel rust

As steel, copper, magnesium, aluminum, et al are exposed to the atmosphere, they react with free flowing air and moisture to develop oxides. The performance of atmospherically exposed metals depends on five main factors: temperature, humidity, rainfall, sulfur dioxide pollution concentration in the air, and air salinity.

None of these factors can be singled out as the main contributor to corrosion. Extensive studies have been conducted on these metals and a predictable corrosion rate for each is available. Corrosion rates may be accelerated by air impurities that dissolve in condensed water or rain water and by dust and dirt settling on the metal surface.

General corrosion rates of carbon steel in different atmospheres and it should be noted corrosion rates in micro-environments can greatly exceed those corrosion rates. Steel in soil is subjected to a range of corrosive forces quite unlike those experienced in atmospheric exposure conditions, and the performance of steel in-ground is not as well understood as is the durability in above-ground applications.

With more than different types of soil identified in North America, corrosion rate in soils is varied and hard to predict. Steel requires oxygen, moisture and the presence of dissolved salts to corrode. If any one of these is absent, the corrosion reaction will cease or proceed very slowly. Steel corrodes quickly in acidic environments and slowly or not at all as alkalinity is increased. The corrosion rate of steel in soil can range from less than 0.

Corrosion of metals in soil is extremely variable and while the soil environment is complex, it is possible to make some generalizations about soil types and corrosion. The main factors that dictate the corrosivity of the soil are moisture content, pH level, and chlorides. These soil conditions are affected by additional characteristics such as aeration, temperature, resistivity, and texture or particle size.

Any given soil is a very heterogeneous material consisting of three phases: solid, gaseous, and aqueous. The solid phase consists of soil particles that vary in size, in chemical composition, and the level of entrained organic material. The solid phase of soils are classified according to their average particle size and chemistry. Traditionally, particles between 0. Because of the smaller particle size and their ability to absorb water readily, clay soils present a higher corrosion rate than sandy soils.

The gaseous phase consists of air entrained in the soils pores. Access of gas air into the soil depends on its permeability. If you have two different metals in electrical contact, and both in contact with salty water, then effectively a battery is made. Current flows, and the energy comes from the corrosion of the metals. Some companies sell blocks of zinc that you can attach to boats so that the zinc corrodes first, protecting the other metals.

Vinegar and bleach have been tried and seem to affect the rusting rate. Fresh iron exposed to a hot atmosphere with plenty of oxygen and water will form a thin layer of rust immediately although if you look at a very short time after exposing the iron surface, you will have a very small amount of rust.

Any of the above variables can affect the rusting rate however. Can you think of more? I read what Tom said about the rate of rusting and stainless steel does rust! I did an experiment on rusting stainless steel and it rusted in water, salt water, vinegar, lemonade and red cordial. Beth, thanks. The rate of stainless steel rusting is very sensitive to what type of stainless it is. The amounts of chromium, nickel etc. When a 'stainless' steel has pockets of nearly pure iron, it will rust.

Mike W. I just wanted to add that contact with other metals will contaminate the Stainless at almost any grade. I see lots of stainless tubes where some pipe-fitter leaves the chain-fall lead laying on it and the next morning there is a rust layer on the s. Although some maybe transfer, that s.

Stainless steels contain more chromium than carbon steels, making it much more rust-resistant. Also, if you were to put carbon steel in the kind of environmental conditions that would exhilarate the build-up of rust, the chances of rusting building up faster would be much higher. Another factor that contributes to how fast rust can form is the thinness of the material, as thinner surfaces are usually weaker and are faster for rust to infiltrate.

This is also the same for materials that have holes in it. Hopefully, now you have a better understanding of how certain metals and the iron found within them play a role. Materials with either more or less iron can affect how quickly rust is likely to form. The conditions that certain iron filled surfaces are surrounded by also play a large role in the amount of rust that builds up, as well as how quickly it forms. When metal heats up, the molecules within the metal are moving and working faster, therefore speeding up the process of rust building up.

For rust to form on metal, all you need is iron and water. If your surface comes into contact with large amounts of water, this will definitely cause rust to form quicker. The type of water also plays another role and can hasten the process of rusting. Saltwater actually rusts objects faster than surfaces subjected to pure water. A lack of rain can also slow down the build-up of rust, compared to environments where there is an abundant amount of rain.