Selecting the appropriate carbon steel alloy

[Sh1ps]

We have an application that requires the building of a mock-up for training firefighters.
The mock-up will be steel (plate/sections and approximately 30 feet long and 10 foot high) and will be exposed to a fuel-rich propane fire (probably in the 600ºC or higher range). The duration of the fire will be sufficiently long to ensure the mock-up has achieved near maximum temperature and since it is a firefighter trainer it will be hit with multiple streams of cold water.

Therefore, the structure will experience repeated heating and quenching cycles and, with a planned life of 10 to 15 years, the number of cycles will be in the 10000 range.

ASTM A387 chrome-molybdenum alloy steel seems to be suitable for the temperature but what effect would the quenching have on performance (mainly buckling)?

Does anyone have any guidance on what steel alloy would suit so that a performance and cost comparison could be carried out.

 

[Navin A S]

The quenching of A387 chrome-molybdenum alloy steel can affect its performance and strength. Quenching will reduce the hardness of the steel, making it more prone to buckling or bending. The best way to ensure that the performance and strength of the steel is not affected by the quenching process is to choose a steel alloy with a higher strength-to-weight ratio, such as ASTM A514 or ASTM A517. These alloys are known to be strong and offer superior resistance to buckling. Additionally, they tend to be more cost-effective than other alloys, making them attractive for use in this application.

 

[oswaler]

I would recommend considering ASTM A516 carbon steel for this application. This alloy has been specifically designed for high-temperature and pressure applications, making it suitable for use in a mock-up exposed to a fuel-rich propane fire. Additionally, A516 has good weldability and is able to withstand repeated heating and quenching cycles without significant loss of strength or ductility.

In terms of performance, the quenching process may cause some distortion or buckling in the steel, but this can be minimized by controlling the cooling rate and ensuring proper heat treatment. A cost comparison between A387 chrome-molybdenum alloy and A516 carbon steel would also be beneficial in determining the most suitable option for this application.

Ultimately, it is important to carefully consider the specific requirements and conditions of the mock-up before selecting an appropriate steel alloy. Consulting with a materials engineer or conducting further research on the properties and performance of different steel alloys in similar applications may also be helpful in making an informed decision.