Effect of Temperature on the Stability of Hardened State of Heat-Resistant Alloys Subjected to Mechanical-Thermal Processing and Multiple Mechanical-Thermal Processing (Vliyanie Temperatury Na Ustoichivost Sostoyaniya Zharoprochnykh Splavov Podvergnutykh MTO i MMTO),
ARMY FOREIGN SCIENCE AND TECHNOLOGY CENTER CHARLOTTESVILLE VA
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A study was made of the behavior of materials hardened by the mechanico-thermal processing method at various service temperatures. The experiments were made on samples cut from tubes from steam super heaters of boilers. Tests for long-term endurance were made on two consignments of samples aa in a state after a standard regime of thermal processing b in a state after multiple mechanico-thermal processing of prenormalized samples by successive deformation of the samples by 1.2, 1.0 and 0.8 with intermediate and final aging at 150C for 6 hours. It was concluded from these tests that it is desirable that industry adopt the multiple mechanic-thermal processing method for increasing the heat-resistant properties and reliability of operation of boiler steels of the pearlite class. It was also found that the optimum regime of mechanico-thermal processing is an effective means for increasing the heat resistance of the alloy EI617 at a temperature of 700C and stresses below 45 kgsq mm. Other tests revealed that mechanico-thermal processing and multiple mechanico-thermal processing of heat-resistant alloys and heat-resistant steels lead to a substantial change in the two principal heat-resistant criteria capacity of the metal for resisting deformation under creep conditions and its capacity for resisting destruction.
- Metallurgy and Metallography
- Fabrication Metallurgy