Some alloying elements ( such as chromium and tungsten ) make the grain of steel finer , thus increasing the hardness and strength of steel .
有些合金元素（如铬和钨）能细化钢的晶粒，从而增加钢的硬度和强度。
T he cast carbon steel , which is with carbon as the main alloying element and little other element , is of high strength , plasticity , tenacity and low cost .
