Kobe Steel’s New High Strength Wire Rod for Fatigue Spring is Adopted by Car Maker

Kobe Steel announced on Wednesday the firm’s high strength wire rod for engine valve spring was adopted by Japanese major automobile maker for the first time, which started the commercial production. The wire rod which is named KHV12N increased the fatigue strength by 50% compared to standard steel product, which downsizes fatigue spring, trims weight of fatigue spring by about 30% and improves fuel economy by about 2% of passenger car. KHV12N is expected to be adopted for four-wheel car and two-wheel vehicle when the timing of model changes. The spring is needed to have high strength and high decay resistance because fatigue spring is used valve operating system of car engine, which is applied cyclic load.Car makers are developing low-fuel consumption engine for the reduction of carbon dioxide against the enhancement of environmental limitation. Energy loss of engine is reduced by downsizing and weight saving of fatigue spring. Pedestrian protection standard for impact was legislated for pedestrian protection. Consequently, car makers is downsizing engine for securement of crumple space in engine room. Kobe Steel succeeded harmless of inclusion which is origination of fatigue breaking by increased addition of alloy, composition control and high pressure by hot rolling mill, and developed KHV12N. Kobe Steel has 50% share of wire rod for fatigue spring in the world. The firm is producing the wire rod in Kobe iron works, and is supplying it to spring makers through drawing makers in Japan and overseas.