Effects of “Residual Stress Controlled TMCP Steel Plate” on Accuracy Ship Blocks

(1^st Report) Influence of Residual Stress of TMCP Steel Plate on Precision of Slit-Slot Cutting

Abstract

TMCP is a technique, which makes it possible to obtain high strength plate with high toughness and good weldability, by accelerated cooling immediately after controlled rolling. The problems that occur with TMCP plates are shape inaccuracy caused by residual stress. If shape inaccuracy take place during cutting or welding, the cost and productivity should be worse because of decreasing in the efficiency of fabrication and the necessity for extra processing to adjust the shape of the material.
A new TMCP steel plate, called as “Residual stress controlled TMCP steel plate”, was developed for use in fabricating the cargo tank and hull structure, which was expected to build accurately ship blocks and to increase productivity through mechanization/automation effectively.
In this investigation, using thermal-elastic-plastic FEM and experiments, the effects of residual stress of TMCP steel plate are quantitatively discussed in slit-slot cutting. The results in this report are as follows.
(1) Residual stress of TMCP steel plate has great influence on the accuracy of slit-slot cutting.
(2) In order to achieve high quality of block accuracy, it is effectively to build ship blocks using “Residual stress controlled TMCP steel plate”.