Investigation Of Weldability Of Hot-Work Tool Steels
Report Number: ASD TR 61-165
Author(s): Sinclair, N. A., Maciora, J. G., Sopher, R. P.
Corporate Author(s): General Dynamics Corporation Electric Boat Division
Laboratory: Directorate of Materials and Processes
Date of Publication: 1961-12
Pages: 138
Contract: AF 33(616)-6519
DoD Project: 7381
DoD Task: 73810
Identifier: AD0273867
Abstract:
The weldability of six hot-work tool steels was investigated to develop optimum welding procedures. Welds were made in sheet and plate with the inert-gas tungsten-arc and inert-gas consumable electrode processes under various welding conditions. Variations in preheat, postheat, and energy input were found to have statistically significant, but practically unimportant, effects on mechanical properties after hardening and tempering. Most mechanical-test failures were initiated in the welds whether or not defects were present. The weld metal retained its heterogeneous microstructure after hardening and tempering even when previously subject to annealing-type heat treatments. Lehigh-restraint-test studies indicated that hot and cold cracking can occur. Low-temperature cracking can be prevented by increasing the preheat temperature. Large-radius Charpy-impact specimens were found to be more satisfactory than the V-notched specimens for these steels. The high-temperature weld tensile strength at 1000°F was 190,000 psi for an H-11 steel; it was reduced to 156,000 after holding at 1000°F for 24 hours. Small-scale pressure vessels were tested both dynamically and statically. Sheet-bulge tests were tested dynamically. One out of four vessels, and three out of five bulge specimens failed at relatively high strengths.
Provenance: Lockheed Martin Missiles & Fire Control
Author(s): Sinclair, N. A., Maciora, J. G., Sopher, R. P.
Corporate Author(s): General Dynamics Corporation Electric Boat Division
Laboratory: Directorate of Materials and Processes
Date of Publication: 1961-12
Pages: 138
Contract: AF 33(616)-6519
DoD Project: 7381
DoD Task: 73810
Identifier: AD0273867
Abstract:
The weldability of six hot-work tool steels was investigated to develop optimum welding procedures. Welds were made in sheet and plate with the inert-gas tungsten-arc and inert-gas consumable electrode processes under various welding conditions. Variations in preheat, postheat, and energy input were found to have statistically significant, but practically unimportant, effects on mechanical properties after hardening and tempering. Most mechanical-test failures were initiated in the welds whether or not defects were present. The weld metal retained its heterogeneous microstructure after hardening and tempering even when previously subject to annealing-type heat treatments. Lehigh-restraint-test studies indicated that hot and cold cracking can occur. Low-temperature cracking can be prevented by increasing the preheat temperature. Large-radius Charpy-impact specimens were found to be more satisfactory than the V-notched specimens for these steels. The high-temperature weld tensile strength at 1000°F was 190,000 psi for an H-11 steel; it was reduced to 156,000 after holding at 1000°F for 24 hours. Small-scale pressure vessels were tested both dynamically and statically. Sheet-bulge tests were tested dynamically. One out of four vessels, and three out of five bulge specimens failed at relatively high strengths.
Provenance: Lockheed Martin Missiles & Fire Control