CN1243170A - Top material for perforating steel pipe - Google Patents

Abstract

The present invention discloses an iron-based rare earth alloy perforating head material whose composition is formed from C 0.16-0.45, Si 0.6-3, Mn 0.3-0.7, Cr 0.6-5, Ni 1.5-2.8, W is less than 0.1, Re 1-5, and the rest is Fe. The said invention can greatly raise the comprehesive property and can greatly reduce production cost.

Description

Steel pipe perforating heading material

The present invention relates to a kind of iron-based rare earth alloy, particularly relate to a kind of heading material that perforating steel pipe is used that is used for.

At present, the perforated material that is used for carbon steel and alloy steel pipe, roughly be divided into alloy tool steel and structural alloy steel two big classes, alloy tool steel has the high and good characteristics of wear resistance of hot strength, but its toughness is relatively poor, is not suitable for using under the operating mode of cold overheated work, easily causes the cracking of perforating head, and cost is relatively more expensive, the production cost height.Adopt plasticity carbon steel or structural alloy steel preferably, also can reach production requirement preferably, but need through special nitrogenize and oxide treatment, production cost can descend greatly.Pierce small-bore steel pipe on the market now and obtained a large amount of utilizations, but the product that such material is made is under the working condition condition of severe, or when piercing the weldless steel tube of larger caliber continuously, just easily cause the surface, top softening, perforating head is out of shape, thereby greatly reduces the work-ing life of perforating head.

Purpose of the present invention just provides a kind of cheap, and the perforating heading material that uses under the suitable different operating modes.

The object of the present invention is achieved like this: the iron-based rare earth alloy of the matrix adopting of perforating heading material, the composition of this alloy (wt%) be C 0.16-0.45Si 0.6-3 Mn 0.3-0.7 Cr 0.6-5 Ni 1.5-2.8 W＜0.1Re1-5 all the other be the Fe element.

Introduce the effect of alloying element in iron-based rare earth alloy below respectively.

C:0.16-0.45 (Wt%), C are the elements that carbide forms, and an amount of carbon can improve the hardness of steel, but the existence of excessive C has reduced the toughness of alloy, is unfavorable for oxidation and nitriding treatment, unfavorable to using under the abominable operating mode, and be unfavorable for forming compact oxide.

Si:0.6-3 (Wt%) adds the cementability that an amount of Si can improve zone of oxidation and matrix, improves the high-temperature resistant tempered performance of alloy, and this is to being absolutely necessary the work-ing life of improving the top.

Mn:0.3-0.7 (Wt%) adds an amount of Mn, has improved the hot strength of perforating heading material greatly.

Cr:1.6-5 (Wt%) adds Cr, can promote the formation of carbide equally, improves the hot strength of material, but too much adding easily causes the production cost of material to improve.

The adding of Ni:1.5-2.8 (Wt%) Ni can improve the hot strength of material.

W＜0.1 (Wt%) adds a spot of W, can promote the formation of carbide, and by the hardness of solution strengthening raising material, too much adding is difficult to form zone of oxidation.

The adding of Re1-5 (Wt%) rare earth, improved the over-all properties of material, can comprehensively improve the quality of base material, greatly reduce material to contain oxygen hydrogeneous, improve the ability of deoxidation dehydrogenation, the adding of rare earth simultaneously descends the content of the impurity such as S, P of material greatly, has improved the anti-cold fatigue lifetime of material, and crystal boundary of material is purified.Because the adding of alloying element and rare earth has facilitated C curve to move to right, and has simplified thermal treatment process greatly.

Introduce embodiments of the invention below.

Iron-based rare earth alloy through smelting, after the casting, is processed into required shape by required composition batching, and whether process of thermal treatment is selected reasonable, and perforating heading material is had significant effects.With the perforating head that is processed into through medium annealing, insulation about 680 ℃, 300 ℃ of air coolings of coming out of the stove, to reach the purpose that eliminates stress, adjusted the weave construction of material, improved the toughness of material, then the material at high temperature oxidation is heated to 950 ℃-1050 ℃ and is incubated 4-5 hour down at 500 ℃-600 ℃ again, to reach the purpose that improves comprehensive mechanical performance, carry out surface oxidation treatment at last, to increase surface smoothness and corrosion resistance, form superhard carburization zone, the life-span of perforating head is significantly improved.The metallographic structure of material after heat treatment is ferrite+granular bainite.Perforating head that material of the present invention is made and traditional comparing, life-span has been improved 3-5 doubly, on tapping machine, use, particularly when piercing greater than the steel pipe of Ф more than 100, can pierce common steel tube continuously 300-500 time/only, pierce alloy steel pipe reach 120-150 time/only, have good high-temperature intensity, wear resisting property.Toughness and anti-rapid heat cycle fatigue all are better than domestic like product (seeing Table 1).Long service life does not ftracture when working under the rapid heat cycle state, lubricated and good heat-insulation effect in perforation procedure, non-stick steel.

Table 1: mechanical property

Claims (1)

1, a kind of steel pipe perforating heading material, it is characterized in that the composition of this material is (Wt%): all the other are Fe C 0.16-0.45 Si 0.6-3 Mn 0.3-0.7 Cr 0.6-5Ni 1.5-2.8 W＜0.1 Re1-5.