EGR GAS-COOLING DEVICE AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide an EGR gas-cooling device without any leakage of cooling water and with improved heat exchange performance and durability by extremely reducing the generation of a stress corrosion crack caused by high- concentration chlorine. SOLUTION: In a multipipe EGR gas cooling device in structure where a group of heat transfer pipes 2 are sealed to and arranged at a tube sheet 3 that is fixed to an area near both end parts of the inner wall of a drum pipe in that a cooling medium inflow port and a cooling medium outflow port are provided at both the end parts by brazing and further the inflow and outflow ports of the EGR gas are provided at both end parts of the drum pipe, the surface of the brazing material of at least a brazing part 5 is covered with a chemical plating metal 6.