Properties of Molybdenum and Tungsten are
very similar, the boiling point and the conductive performance is outstanding,
the linear thermal expansion coefficient is small, easy processing of tungsten.
Molybdenum is a kind of chemical element, chemical symbol is Mo, its atomic
number is 42, is a kind of gray transition metal. Pure metal molybdenum is
silvery white, very hard. Add a small amount of molybdenum to steel, hardened
steel. Molybdenum is a very important nutrients to plants, were found in some
of the enzyme. And Tungsten is a kind of steel grey or silver white metal, with
high hardness and hard melting point. Its atomic number is 74, the atomic
weight of it is 183.85. The melting point of it is 3410℃, the boiling point of it is 5900℃, thermal conductivity is 10 to 100
for 174 w/m*k. Slow evaporation at high temperature, the thermal expansion
coefficient is very small, the expansion coefficient at 0 to 100 ℃, 4.5 × 10-6 · K-1. The resistance of tungsten is
about 3 times larger than the resistance of copper.
lloy steel, stainless steel, tool steel and
cast iron is the main field of application of Molybdenum, the Molybdenumproduction determines the demand, the effect of Molybdenum in the steel is as
following:
1. To reduce the cooling rate to the
appropriate values to obtain a hard martensite, which can improve the strength,
hardness and toughness of a large section components.
2. Reduce the temper brittleness.
3. The resistance to hydrogen embrittlement.
4. The resistance to sulfide stress
cracking.
5. Improve the high strength.
6. To improve the corrosion resistance of
stainless steel, especially the anti chloride pitting.
7. To improve the high strength low alloy
steel welding performance.
As steel Molybdenum alloy additives are the
most important uses , according to statistics of 1986, which accounts for the
total world consumption of 83% of Molybdenum. And where a steel containing
Molybdenum World crude steel production has accounted for 1/10. Therefore,
Molybdenum steel than is often used as an industrially developed country or one
of the signs.
