| Date | September/October 2005 |
| Volume | 11 |
| Issue | 5 |
| Return to Journal Index | |
September/October 2005 Inspectioneering Journal Article Index
Metals will slowly deform under stress and higher temperatures by the mechanism known as creep. The amount of creep deformation that will be experienced is highly dependent upon the level of stress, level of temperature and material properties....
Another form of metallurgical degradation at higher temperatures is called sigma phase embrittlement. As the name implies, a metallurgical phase change occurs in some stainless steels when they are heated above about 1000F (540C).
Spheroidization is a rather technical term that describes a metallurgical aging phenomena that results in loss of mechanical and creep strength. It occurs when carbon and low alloy steels are exposed to temperatures in the range of 850F - 1400F...
Strain-aging problems are another form of metallurgical degradation and thankfully are not very common and becoming less so; but since strain-aging does still occasionally occur, it still makes the list of one of the “99 diseases of pressure...
Temper embrittlement is another form of metallurgical degradation resulting from exposure of susceptible low alloy steels to higher temperature ranges, usually in service, but can occur to some extent even during heat treatment. And, once again, if...
Titanium (Ti) hydriding is another somewhat unusual metallurgical degradation phenomena that can result in brittle fracture. Unlike many other steel embrittlement phenomena, this one most often occurs in thin wall Ti tubes that have been selected...
Is calibration of NDT or any other equipment necessary? The answer is certainly Yes! But a question still arises. Why? Because in the case of NDT it is required by national and international standards. Many NDT standards require that a system of...
