Brief analysis new product steel 42CrMoS4 element control specifies requirements for for general applications.
Carries on the summary to company new product 42CrMoS4
aluminum smelting, pointed out in the production process exists question and solution, thus enhances the company product the market competitive power.
: New product smelting, Chemical composition,Control.
Little fluctuation of grain refinement of 42CrMoS4
(the German brand is the company occupied the market out of the country's new kinds of steel, the steel technology for EAF + LF refining furnace + VD vacuum degassing furnace + die casting ingot by slow cooling demolding finishes, heating and forging and processing to obtain austenite grain size of 5 ~ 8 level of fine grain steel for the final product. For metal material chemical composition control in a narrow range is the same product performance stability, improve the company's products in the market competitiveness of the key. It is exported to the European market for high value-added steel. The steel in casting, slow cooling, finishes, heating, forging heat treatment in our company can better Lower end due to the control of individual control, but in the smelting process in the steel composition range is narrow, especially carbon and sulfur elements influencing factors more, often appear the arc furnace and vacuum degassing furnace carbon special instead of ordinary chrome molybdenum steel and vacuum furnace sulfur control in the limit again to LF refining furnace sulfur addition or desulfurization, thereby increasing the power and raw materials consumption, the company production cost greatly increased performance delivery rate and therefore affected, even may face default penalties, and changed into ordinary chrome molybdenum steel price caused by the direct loss of benefit. In order to solve the carbon sulfur component is more difficult to control the problem, we carried out a number of analysis , in-depth discussion of the research, take some practical measures, so that the 42CrMoS4
steel smelting problem can be solved basically. This paper mainly discusses the carbon sulfur elements out of line causes and prevention measures.
; control of the end of treatment to the end of the content of hydrogen gas in the steel composition control of silicon, manganese, molybdenum, aluminum alloy element content in the LF refining process is easy to control in a narrow range, P elements in the smelting process can be reduced to a low level, copper, nickel, titanium, tungsten, vanadium and other residual elements can also by optimizing the mixture obtained better control and steel by vacuum treatment also can be reduced to a prescribed range. Due to the oxidation of vacuum refining process in many aspects of carbon elements have a certain effect of elemental sulfur content requirement for a range of values, and slag basicity, temperature, oxygen, slag and other aspects will affect the Sulfur in the steel slag balance, combined with the actual situation in the production of the slag is not convenient to analysis. So for the 42CrMoS4
steel smelting process in our company's carbon, sulfur element control is more difficult.
At the beginning of the resulting in tapping the early lead to improper mixing ratio of early excessive. Mixed at the beginning of, at the end of the oxidation of elemental carbon special reason mainly has the following several aspects: a. the end-point carbon control high performance in the end-point carbon free sampling representative sampling analysis value than the actual furnace uniform carbon value low. Reduction of carbon containing reducing agent using partial, before tapping unburned net, tapping slag flushing stirring jump carbon reducing slag, slag thin carbon deoxidization agent is added after recarburization process too much. The reduction of carbide slag tapping before the destruction of the atmosphere carburizing. Arc furnace reduction, LF refining furnace refining and VD vacuum treatment process of steel ladle has a power pole piece or the electrode head off not found by Mixing flushing and refining argon stirring scour in electrode carbon over Frandlin early carbon reduction low before tapping furnace carburizing, improper operation of recarburizing agents failed to immediately bear fruit, refining furnace again carburizing ignored slag carburant caused by excessive carbon, refining of component temperature adjustment end, but the carbon oxygen remover unburned net vacuum degassing and slag are washing makes the liquid steel jump carbon.
VD vacuum treatment end elemental sulfur into limited reason mainly in the following two aspects: A. steel in the original sulfur content is too high, slag sulfur saturation, vacuum treatment desulfurization rate lower than that of the normal lead to VD end adjustment of high sulfur slag alkalinity. Didn't grasp well, high alkalinity caused by VD vacuum treatment process in desulfurization rate of high end of sulfur is lower than the lower limit; lower alkalinity caused by VD vacuum treatment process in desulfurization rate is low and even back to sulfur end of sulfur is higher than the upper limit.