introduction of metal materials
metal materials are most widely used in our daily lives and industrial uses.there are several categories of metal materials including steel, iron ,nonferrous material etc.and steel is the most commonly used among them. iron is the main element in steels,other elements including all kinds alloy elements added and foreign elements.the vast varieties in the properties of steel are due to the differences of these alloy elements regarding categories and percentage.such as ordinary carbon steel ,stainless steel, alloy steel etc.carbon is playing an indispensable role in the functioning of the alloy elements.
iron makes up the majority percentage in all kinds of steels.several alloy elements can be mostly seen in the steel such as carbon(c),silicon (si), manganese(mn),phosphorus(p),sulfur(s),chromium(cr),nickel(ni),molybdenum(mo),titanium(ti) ,vanadium(va) etc.
often we see phosphorus and sulfur as foreign substances,the less percentage these two elements make up the higher quality the steels are.
steel can be simply classified into three categories in accordance with the alloy elements added to it as: carbon steel,alloy steel, stainless steel.carbon steel is the kind with only the alloy elements of c,si, mn,p,s,and can be categorized according to the percentage p and s are making up as :ordinary carbon steel(p and s each less than 0.04%) like:Q215A, Q235BF and high quality carbon steel(p and s each less than 0.03%) like:20#,45#,16Mn etc.alloy steel also contains elements cr,mo,v with less than ten percent in addition to the five ordinary elements above mentioned.
stainless steel:with a as high as 20 percent percentage of alloy such as cr,ni,etc added.
for example:
in japan and the united states:304(C