WE Student Seminars: Eun Jang & Yuxiang Zhang

All dates for this event occur in the past.

111 EJTC
1248 Arthur Adams Dr
Columbus, OH 43221
United States

Eun Jang

Graduate Student, Welding Engineering, advised by Dr. Boian Alexandrov

Temper Bead Welding

Abstract

The objective of this work was to develop a procedure for evaluation and quantification of the tempering efficiency of corrosion resistant weld overlays used in the power generation and oil and gas industries. Three two-layer weld overlays of Alloy 625 on Grade 22 steel plates were produced using GTAW cold wire procedures. Typical welding parameters corresponding to low, medium, and high heat input were utilized. The overlays consisted of nine beads on the first layer and five to seven beads on the second layer. The weld thermal histories experienced in the coarse-grained heat affected zone (CGHAZ) were measured with Type K thermocouples and recorded with a 55 Hz sampling rate. Two rows of seven thermocouples were used in each overlay: one row located in a mid-bead position beneath the center bead of the overlay and the other row located in the nearest bead overlap position. Additionally, one Type C thermocouple was plunged into the weld pool of a second layer weld bead. The acquired thermal histories and the CGHAZ hardness at the thermocouple locations were evaluated to quantify the tempering efficiency in each welding procedure. The weld thermal histories with peak temperatures between 500°C, assumed as the minimum tempering temperature, and the base metal Ac1 temperature were considered as tempering thermal cycles. The number of tempering thermal cycles and the sum of tempering cycle’s peak temperatures in each thermocouple location, as well as the corresponding hardness were used to quantify the tempering response efficiency for each of the three welding procedures. The results of this study will be used for validation of a computational model-based approach for prediction of tempering response and optimization of temper bead welding procedures.

Bio

Born 1996. High School Diploma 2015 - Olmsted Falls High School B.S. Welding Engineering - OSU 2019 Pursuing M.S. Welding Engineering - OSU 2021


Yuxiang Zhang

Graduate Student of OSU Welding Engineering 

Thermal fatigue and thermal shock test on high temperature alloys 

Abstract

High Ni high Cr materials with good oxidizing and carburizing resistance at high temperature failed after thermal fatigue and thermal shock. The objective of the study is to design test procedure for comparing crack susceptibility of different materials

Bio

Welding Engineering graduate student from China. Once sang song on China Central TV. Will keep working out until I'm too old to.