Hot work steel

The major portion of drill string is composed of drill pipe. The drill pipe is manufactured by the seamless process. According to API Specification 5A (Thirty-fifth Edition, March 1981), seamless pipe is defined as a wrought steel tabular product made without a welded seam. It is manufactured by hot working steel or, if necessary, by subsequently cold finishing the hot worked tabular product to produce the desired shape, dimensions and properties. 

L.J. Yang, Wear coefficient of tungsten carbide against hot work steel disc with two different pin settings. Wear 257 (2004) 481-495. 

Manifolds designed to operate at very high temperatures are made of hot work steel, e.g., DIN 1.2343 or DIN 1.2714. 

The main property required of sleeve and jacket is a high degree of toughness, when on the other hand a lower resistance to wear is acceptable. Steels treated to an ultimate tensile strength of 130 to 150 kg/mm for liners, 110 to 120 kg/mm for sleeves and 90 to 110 kg/mm for jackets are generally chosen. Table 14 shows very clearly the limits for the retention of hardness and for the range of application of various hot working steels with the extrusion temperatures of the most important alloys. 

As seen in Figure 1.215 to Figure 1.217, processing of continuous fiber-reinforced thermoplastic materials is done in heated molds. These are mostly manufactured from mold steels for warm processing (so-called hot work steels). Well suitable steels are for example 1.2311,1.1730, and 1.2710. A useful help for selecting the appropriate mold steel is the so-called Key to Steel (Stahlschliissel Verlag, Marbach, Germany). Different steels and their composition and suitability are therein defined. 

FIGURE 2.45 Ejector pins hardened from hot work steel... 

Thus, all the benefits of the system nozzles can be used for single applications without a hot runner manifold, even If not driven with an adjacent machine nozzle. The nozzle bodies are usually made from special hot work steel. This guarantees a high compressive strength, even for continuous temperatures well above 300 °C. With these nozzle concepts, plastics with filler contents of more than 40% and VO-adjusted materials at injection pressures of 2,000 bar or more can be reliably processed. Figure 2.58 shows a typical representative of the manufactured products family with this nozzle series. High processing temperatures, a narrow process window, and the risk of abrasive and chemical wear of the mold components are characteristic of this type of technical components. 

FIGURE 4.83 Tempering curves for the cold work steel 1.2767 (45NiCrMo16) and the hot work steel 1.2343 (X37CrMoV5-1)... 

R. Thome and W. Dahl, On the crack susceptibility of high alloyed tool steels during continuous casting and in the temperature region of hot working, Steel research, 66 (1995), 63-71. 

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