What is the stainless steel?

Stainless steel chromium over 12% content, is it get rusty one iron base of characteristic alloy steel referred to as to have.

What is it to decorate the type of using the stainless steel dailily?

The commonly used stainless steel type calls trade mark of our country of sus304 (Japanese trade mark standard ) OCr18Ni9 on the market vulgarly at present.

Is the same kind of specification type material the harder the thicker?

It needn't be. Market at present is it is it make material because of the limitations of production technology , content too high containing a small amount of nitrogen is it rise to hardness to lead carbon have to look through partly to have, impossible Cr in addition, Ni reduces the content, the hardness will rise too. Two material toughness these able to bear corrosivity can drop too.

Will certainly not the stainless steel get rusty? Is it apt to get rusty under what condition decorate the stainless steel?

No. The corrosion takes place to decorate the stainless steel, besides one's own defect, in the environment that is in, such as the humidity of the air, the temperature of the air, the speed that flow, flow in the direction, there are great relations between air composition and quantity containing impurity ,etc.. And corrodes the speed and is smaller than 0 weakly while corroding the medium in the atmosphere. 01mm /the annual,namely not thinking " corrode totally ". But in a medium of CL (such as the salt), sulphuric acid, oxalic acid (wash dailily in the outer wall of the project), hydrochloric acid, being clean to will get rusty in helping, porcelain should use neutral material (such as branch water ) wash in order to is it corrode medium adhere to and get rusty to reduce often in the course of maintaining, should prevent sharp object from scratch with is it influence appearance and structure get rusty among destroying brilliant to avoid in addition.

Why is apt to get rusty after stainless steel cold and out of shape?

Stainless steel through curved, button, produce location appear by mistake after rolling over(whether namely the structure is destroyed among inside brilliant), a bit easier to produce to corrode but get rusty.

Classification of the stainless steel

Stainless steel can according to use, chemical composition and metallography organize classification on the whole. , in order to make up basically , the difference changing of joining amount of every element by 18% of the chromium - 8% of the nickel with the steel of the systems of, and develop the kind of steel of different uses. Classify chemical composition :

(1)CR series, iron plain system arrange, horse the system ranks
(2) CR-NI series, system arrange, unusual series, is it happen series of hardenning to roll over

Classification organized with the metallography :

(1)Body stainless steel of
(2)Ferrite stainless steel
(3)Body stainless steel of horse
(4)One pair of lookses stainless steel
(5)Precipitate and harden the stainless steel

Decisive action in the stainless steel of chromium

Determine stainless steel element that belong to have only one , this chromium , each stainless steel contain certain amounts of chromium. Up until now, the stainless steel not including chromium yet. The chromium becomes the main element which determines stainless steel performance , the basic reason adds the chromium as after the alloying element to the steel, impel inside contradiction sport its to is it resist destroyed to corrode develop to help.

This kind of change can prove from the following respect .

1. The chromium makes the electrode electric potential of the firm solution of iron base improve by
2. Chromium absorb electron of iron make the iron passivation. The passivation is the phenomenon causing the metal and corrosion-resistant performance of alloy to be improved because the positive pole reacts and is prevented from. There are a lot of theories of forming metal and alloy passivation, there is a theory of membrane mainly , absorb and touch upon the electron to arrange the theory .

The role in stainless steel of nickel is just brought into play after cooperating with chromium

The nickel is fine and corrodes materials , it is the important alloy element of the alloy steel too. The nickel forms the element of the body of in the steel, but the nickel steel of low carbon should get pure the body is organized, nickel content should be up to 24%; Make steel corroding performance change notably among some medium only when include 27% of nickel. So the nickel can't form stainless steel alone . But the nickel and chromium exist in the stainless steel at the same time , the stainless steel including nickel has a lot of valuable performance . Can know the situation based on above, the nickel is regarded as the role in stainless steel of alloying element , lie in it makes the organization of the high chromium steel change , thus make corrosion-resistant performance and craft performance of the stainless steel win some improvement.