do we need the best material at any cost?

In the oil and gas industry from upstream to downstream using various types of metal materials. This material is used for operating temperature – 40 ^oC to 1,000 ^oC. How do we choose the best materials for oil and gas facilities? Facility engineers are often confronted with conditions to choose the best type of material. In general, there are 3 main criteria that are often used.

1. best material for possible operating conditions.

These operating conditions will largely determine the required material properties. For example, we will use pressure vessel on operating conditions at high pressure and temperature, then we will need material that has high strength property and holds at high temperature. There is only a rare chance that a material has a maximum or ideal property combination. So, it may be necessary to trade off one property to gain another property advantage. Classic examples involve strength and ductility. usually, the material that has high strength will only have limited ductility. In such cases, a reasonable compromise between two or more properties may be required.

2. material property damage that may occur during operation.

Property of material is not always the same throughout the life of the operation. For example, significant reductions in mechanical strength can result from exposure to high-temperature or corrosive environments. In general, materials that operate at high temperatures and for a long time, will suffer creep.

3. Economic consideration to get the best material

Finally the main consideration is the economy: What will happen when the cost of the product gets so high? A material can be found that has an ideal set of properties but is very expensive. Here again, some compromises are inevitable.

Initially, the fresh graduated mechanical engineer will have difficulty compromising on the above 3 things. But along with the many experiences and insights, he will get used to choosing the best material to use.