Molybdenum (Mo)

Molybdenum (Mo)
In steel molybdenum can improve its quench-hardening ability and hot strong property. Prevent brittleness, increase the residual magnetism and coercive force and in some resistance to corrosion medium.
In the tempering steel, molybdenum can make large cross-section of the deep, quenching quenching parts thoroughly, and improve the resistance of the steel back to watery or tempering stability, the parts can be in a higher temperature tempering, so as to effectively eliminate (or lower) residual stress and improving the plastic.
In the carburizing steels is in addition to the above molybdenum in the effect, still can be in carburized layers of lowering the carbide grain boundaries in the tendency to form a continuous mesh, reduce the residual carburizing layer austenitic, relative to increase the surface layer wear resistance.
In the forging die steel, molybdenum can also keep steel have relatively stable hardness, increase of deformation and cracking and wear resistance, etc.
In stainless steel acid, molybdenum can further improve on an acid (such as YiSuan, acetic acid, oxalic acid, etc.) and hydrogen peroxide, acid, sulfite, sulfate and acid dyes, bleaching of such as fluid of resistance to corrosion. Especially because of molybdenum to join, prevent the existence of chlorine ion produced some corrosion tendency.
About 1% of the W12Cr4V4Mo containing molybdenum HSS high wear resistance, tempering hardness and red rigid, etc.
(1) for the organization and show do steel heat treatment effect
A, molybdenum in steel can be solid soluble in ferrite, austenitic and carbide, it is to narrow the austenitic phase of the element
B, when steel content is low, and iron, carbon composite of cementite; When high content can be formed steel special carbon dioxide
C, molybdenum improving steel its quench-hardening ability, and its function is chrome strong. And change in manganese
D, molybdenum improve the stability of tempering steel, alloy elements exist as a single, increase of steel brittleness; And chromium, mn and coexist, molybdenum and reduce or suppress because other elements in the brittleness
(2) for the role of the mechanical properties of the steel
A, molybdenum ferritic to have solid solution strengthening effect. But also improve the stability of carbide. So as to improve the strength of steel
B, molybdenum to improve steel and toughness and wear resistance of the deformation of the play a beneficial effect
C, due to strengthen the deformation after molybdenum and softening temperature and restore recrystallization temperature, and increase the strong increase of ferrite creep resistance, inhibit the cementite in 450-600 ℃ of gathered. Promote special carbide exhalation, thus become the hot strong sex improve steel the most effective alloy element
(3) of steel of physical, chemical and process performance role
A, in carbon 1.5% of magnets, 2%-3% of the steel improve magnetic feeling and coercive force remaining
B, in reducing acid and strong oxidizing salt solution can make steel surface passivation. So molybdenum generally improved steel can be corrosion resistance, prevent steel in the pitting chloride solution
C, molybdenum content is higher (> 3%) make steel of oxidation resistance deterioration
D, containing molybdenum not more than 8% of the steel can still forging, rolling, but the content is higher, the hot working on the deformation resistance of steel increases
(4) in the application of steel
A, in conditioning and carburizing steels, spring steel, bearing steel, steel, stainless steel, heat-resistant steels, acid pumpbody has been widely applied in all
B, chromium MuGang in many cases can replace nickel chrome steel to make important components
C, our country oil-rich molybdenum, but within the scope of the reserves in the world is not rich. MuGang in our country should contain the appropriate development, but molybdenum is an important strategic materials, rational and economical use should be paid attention to.