Research on High-Strength Steels with an Improved Resistance against Weld Cracking

摘要

Current American practices are surveyed to determine which weld cracking tests are used, and what methods are used to prevent and control weld cracking. The cracking resistance of a newly developed quenched and tempered High Strength Low Alloy (HSLA) steel. K-TEN8OCF, is researched. Using the Tekken self-restraint weld cracking test and Gas Metal Arc (GMA) welding, the new steel is compared against two commonly used high strength steels at various preheat levels. An investigation is made into the possible impacts of the cracking test results, based particularly upon the survey of practices. The steel test plates were subjected to X-ray, dye penetrant, and macroscopic and microscopic examinations to determine the extent of any existent cracking. It was found that the HBLA steel exhibited an excellent resistance to cracking, even when welded without the use of preheat; whereas, the T-1 and HY-80 steels had to be preheated in order to ensure cracking did not occur.