You may already know a lot about the durability of stainless steel against a variety of stress factors as this is well documented. The tensile strength and impact tolerance of steel far outweigh that of many other metals, but what isn’t as well known is the heat resistance of stainless steel. In other words.. what degree of heat can stainless steel endure before melting?
While the question is certainly a valid one, there isn’t a ‘one size fits all’ answer. The reason is that there are many types or formulations of stainless steel. These range from the more common 304, 316, and 317 stainless steels known for their degrees of carbon, through to Ferritic steels (steels which are high in chromium) such as 430 and 434 and tempered and hardened 410 and 420 steels. Because of its compound make up, each group type will have a different melting point.
As an example, here is a list of melting points for the different grades of steel
- Grade 304 – 1400 -1450°C
- Grade 316 – 1375 -1400°C
- Grade 410 – 1480 -1530°C
- Grade 420 – 1450 -1510°C
- Grade 430 – 1425 -1510°C
- Grade 434 – 1426 -1510°C
You’ve probably noticed that each grade of steel is expressed as a range rather than a specific number. This is because, even with a specific alloy type there remains the possibility of tiny variations in the formation which can and will affect the exact melting point.
Why exacting melting points shouldn’t be your only temperature concern
If you plan to use stainless steel for structural or supporting reasons in a heated environment, the actual melting point shouldn’t be your only temperature consideration. At high temperatures all alloys will lose a certain amount of tensile strength and stainless steel is certainly no exception. Experiments show that even before reaching the critical melting point, stainless steel that was once strong, becomes less rigid and more susceptible to bending.
As an example steel that retains 100% of its structural integrity at say 850°C is likely to lose around 50% of its tensile strength when the temperature hits 1000°C. What this means is that if a structure was designed to carry say 1000kgs in weight, it would only be able to hold 500 kgs of weight safely when exposed to the higher temperature. Any more weight and the structure could bend significantly.
But that’s not all to take into consideration….
In some cases high temperatures can affect the oxide layer used to protect stainless steel from corrosion making it more susceptible to rusting in the future. High temperatures can also cause scaling on the metal’s surface which can also affect the metals ability to perform to full capability.
If you’d like to know more about safe working temperatures for stainless steel parts and components then come and talk to the experts at Metro Steel. We’ve been fabricating steel products for many years and have the ability to turn your ideas into fully functioning prototypes. Contact us on 07 3204 1000