Review Of Recent Developments In Metals Joining

Strengthening methods for ultrahigh- trength s e ls are describ a i cus ed. The objective is to provid the designer with an idea of t e prop rti s which can be developed by various proces es and th operating personnel with an outline of procedure The processes include the conventional quench and t per, martempering, Ausforming, prestrain a d r p r, pr cipitation hardening as it applies to special steel compositions designed for this purpose (i.e., mar gi g), and austempering. Included for each method is ou line of the proces bul ion of the chanical properties whic c n be expected, iscussion of ny limitations which the process may have, and if available, an explanation of the mech nis of strengthening. (Author).

Tensile properties that may be obtained in highstrength alloys for use from -423 to 4000 F are presented. Representative properties are given for high-strength alloys of the common base metals having melting points from that of Mg to that of W. The primary purpose is to illustrate the upper limits of the yield strength to density ratios for these alloys within the range of possible service temperatures. The temperature and time effects are combined in the LarsonMiller parameter for 0.2% offset yield strength or 0.2% plastic creep strain for limited creep data. The time for 0.2% offset yield strength determination is assumed as 0.01 hr. This permits use of yield-strength data from tensile tests and 0.2% plastic-creep-strain data from creep tests in the same charts. The LarsonMiller parameter may not be strictly applicable for certain alloys. In some instances, the data are for current production alloys with standard heat treatments. (Author).