In order to provide helps for industrial applications

this paper studied the microstructures and properties of iron-base powder of different compositions. First

iron-based alloy coatings were prepared by plasma spray equipment

and then cracks on surface of coatings were tested by penetrant testing. Second

chemical compositions were tested by direct reading spectrometer

and then analysis the influences of chemical compositions on microstructures. last

Rockwell hardness and wear quantity of iron-base powder coatings were tested by Rockwell hardness tester and pin-on-disk wear testing machine

and then study the influences of microstructures on hardness and wear. Through above tests

we found that

firstly when the value of Creq/Nieq is 0.26

crack appears on the surface of coating. Secondly microstructures are influenced by the values of Creq and Nieq

so the matrix is mainly austenitic.Thirdly there is no linear relationship between Creq/Nieq of hardness and wear resistance

and the hardness of five iron-base powder is all above 40 HRC. Fourthly

the wear resistance of coatings increases with the increase of hardness

and the wear loss of Fe5 is only 3.65g

but when the hardness of iron-base powder reaches 59 HRC

wear resistance decreases. So

according to the above research

we can believe that the chemical compositions of the claddings determine microstructures

especially c content. When the carbon contents increase

hardening phase is formed in coatings

such as M

7

C

3

so hardness and wear resistance are higher. But

when the hardness reaches a certain value

the appearance of crack causes the hard phases spall

wear resistance decreases.