A Study on Weldability of a New Ultra-High-Tensile-Strength Steel (Report 1)
1967 Volume 36 Issue 7 Pages 766-773
Details
1967 Volume 36 Issue 7 Pages 766-773
A new ultra-high-tensile-strength steel was developed by addition of proper amount of AlN, which is known as IN-treatment, to a commerical 80 kg/mm2 high tensile strength steel. The development was carried out as a joint work with the YAWATA IRON & STEEL CO., LTD, Prior to use for steel structure or pressure vesseles, various weldability tests were undertaken, and it has been established that the ultra-high-tensile-strength steel has completely satisfactory weldability. After the tests, authors reached following conclusions.
1. Weld-joint properties are satisfactory and quite comparable to those of base metal, when optimum welding condition is applied.
2. To increase the ductility in free bend specimen of weld-joint, it is necessary to keep weld-heat-input to a range of 20, 000-32, 000 joule/cm.
3. Preheating to 120°C or higher is quite effective to avoud cracks in 25 mm thick weld-joint.
4. Some deterioration is observed in weld-heat-affected-zone in V-notch charpy impact test for weldment. Authors have pointed out the need for further investigation of the phenomenon.
