Journal of Welding and Joining

6: Journal of KWJS. 2012;30(6):10-14. Published online December 23, 2012.
DOI: https://doi.org/10.5781/KWJS.2012.30.6.10; A Welding Characteristics of Large Caliber-Thick Plate Pressure Vessel Low Alloy Steel (Mn-Mo); Jong-Seok Ahn^*, Jin-Keun Park^*, Jae-Yeon Yoon^*; Corresponding author: Jong-Seok Ahn ,Email: ahnjs001@ewp.co.kr

Abstract: Recently the low alloy steel plate made with manganese-molybdenum is used widely in steam drum and separator of the new coal-fired power plant boiler. This material is suitable for the vapor storage of high pressure and high temperature. The high temperature creep strength of Mn-Mo alloy is higher than the carbon plate(SA516) that used in the subcritical pressure boiler. It reduces the thickness of the pressure vessel and makes the lightweight possible. Recently in the power plant boiler operation and production process, the damage has happened frequently in the heat affected zone and base material according to the hydrogen crack and delayed crack. This paper describes the research result about the damage case experienced in the boiler steam drum production process and present the optimum manufacture method for the similar damage prevention of recurrence.

Keywords :Welding, Heat affected zone, Hydrogen crack, Delayed crack, Steam drum, Shield metal arc welding, Flux core arc welding