CN104975125A - Auxiliary material used for production of nodular cast iron QT400-18 - Google Patents

Abstract

The invention discloses an auxiliary material used for production of nodular cast iron QT400-18. 100% of the auxiliary material comprises 3.55 to 3.85% of C, 2.0 to 2.4% of Si, 1.3 to 1.8% of Mn, 0.001 to 0.04% of P, 0.001 to 0.01% of S, 0.035 to 0.045% of Mg, 0.001 to 0.05% of Cr, 0.001 to 0.05% of Cu, and 0.003 to 0.005% of Sb. In production processes, quality stability is high; and excellent mechanical properties, such as high toughness and high strength, are achieved.

Description

A kind of auxiliary material produced in spheroidal graphite cast iron QT400-18 controls

Technical field

The present invention relates to a kind of auxiliary material produced in spheroidal graphite cast iron QT400-18 to control, be especially applicable to the raw material producing wind-powered electricity generation generating set.

Background technology

Because the environment of wind power plant work is relatively complicated, therefore higher requirement is proposed to the quality of component, require can normally work in-40 DEG C of environment, so QT400-18 material must possess excellent mechanical property, toughness reguirements is higher, and impact property at least reaches more than 7J under-40 DEG C of conditions.Therefore require higher impact property, the number of graphite ball in necessary guarantor unit area is more than 200, and pearlitic content more than 7%, so in fusion process, strictly can not control the pearlitic element of promotion.The factors such as the geographical position of separately installing due to wind power equipment, the transporting and hoisting expense causing component to lose efficacy to produce is high, therefore external, the inner quality proposition requirements at the higher level to component, this kind of material capability is close to technically pure iron.

Summary of the invention

The invention reside in provide a kind of and can meet high tenacity, the mechanical property of high strength, impact property at least reach more than 7J under-40 DEG C of conditions and auxiliary material in the production spheroidal graphite cast iron QT400-18 that in making processes, quality stability is higher controls.

The present invention is achieved through the following technical solutions: the auxiliary material that this kind is produced in spheroidal graphite cast iron QT400-18 controls, auxiliary material comprises C, Si, Mn, P, S, Mg, Cr, Cu, Sb, and the auxiliary material percentage composition in each spheroidal graphite cast iron QT400-18 of hundred parts is respectively: described C controls 3.55 ~ 3.85%;

Described Si controls 2.0 ~ 2.4%;

Described Mn controls 1.3 ~ 1.8%;

Described P general control is 0.001% ~ 0.04%;

Described S controls 0.001 ~ 0.01%;

Described Mg controls 0.035 ~ 0.045%;

Described Cr controls 0.001 ~ 0.05%;

Described Cu controls 0.001 ~ 0.05%;

Described Sb controls 0.003 ~ 0.005%.

The spheroidal graphite cast iron QT400-18 material capability that various auxiliary material add-on directly affects, the defects such as the too high easy generation graphite floatation of C, produces considerable influence to mechanical property, and too low then easy appearance is bad, also affect the mechanical properties; Si is the alloying element promoting that graphitizing is the strongest, has obvious effect to the tensile strength improving material; Mn element promotes one of spheronisation effective element, but this kind of too high easy generation cementite of constituent content; P element has a certain impact to molten iron flow, but this kind of element easily produces iron phosphide eutectic, has a strong impact on mechanical property; S element belongs in magnesium iron material element, has a strong impact on the formation of globular graphite, therefore after nodularization, (after stove) content controls below 0.01%; Mg element is the important element promoting that globular graphite is formed, and affects nodularization effect, then easily cause shrinkage cavity (pine) defect and the fragility of material is increased when Mg remains too high when Mg remains too low; Cr element has certain effect to pearlitic formation, but this element hardness high fragility is large, very easily produce cementite, have a strong impact on the mechanical property of QT500-7 material, therefore Cr controls below 0.05%; Cu promotes the effective element that perlite is formed, and improves tensile strength successful; Sb element can crystal grain thinning in certain content range, improves the mechanical properties such as the impact of material, promotes the extension property of material, but exceeds certain content and then cause pearlitic a large amount of generation, therefore Sb constituent content is to control within 0.003 ~ 0.005%.

Embodiment

By embodiment, the present invention is described in further detail.

The auxiliary material that the present invention produces in spheroidal graphite cast iron QT400-18 controls, and auxiliary material comprises C, Si, Mn, P, S, Mg, Cr, Cu, Sb, and the auxiliary material percentage composition in each spheroidal graphite cast iron QT400-18 of hundred parts is respectively: C controls 3.80%; Si controls 2.3%; Mn controls 1.6%; P controls 0.02%; S controls 0.009%; Mg controls 0.040%;

Cr controls 0.045%; Cu controls 0.046%; Sb controls 0.0045%.

Claims (1)

1. the auxiliary material produced in spheroidal graphite cast iron QT400-18 controls, and auxiliary material comprises C, Si, Mn, P, S, Mg, Cr, Cu, Sb, it is characterized in that:

Auxiliary material percentage composition in each spheroidal graphite cast iron QT400-18 of hundred parts is respectively:

C controls 3.55 ~ 3.85%;

Si controls 2.0 ~ 2.4%;

Mn controls 1.3 ~ 1.8%;

P general control is 0.001% ~ 0.04%;

S controls 0.001 ~ 0.01%;

Mg controls 0.035 ~ 0.045%;

Cr controls 0.001 ~ 0.05%;

Cu controls 0.001 ~ 0.05%;

Sb controls 0.003 ~ 0.005%.