JPS59222565A - Production of precipitation hardening type alloy member - Google Patents

Abstract

PURPOSE:To obtain a member which can satisfy the requirments specified for a heat treatment without deformation and residual stress in a titled process for producing said member in which an aging treatment, machining or straightening stage is included by dividing the aging treatment stage and performing the other stages mentioned above between the divided stages. CONSTITUTION:Raw materials are melted and cast and the casting is subjected to decomposing, forging and annealing heat treatment then to straightening A of bend with a cold press in the case of producing, for example, a pump shaft of ''Monel K500''. The pump shaft is then subjected to an aging heat treatment A of air cooling at the same temp. as in the prior art in which the heat treatment is performed by as much as half the time specified by standards and the pump shaft is machined and is again subjected to straightening B. Said shaft is in succession subjected to the aging heat treatment B under the same conditions as those for the treatment A to complete a product. The precipitation hardening type alloy member which is free from the deformation and residual stress occuring in the machining and aging treatment and can meet the requirements specified for the heat treatment of the material is thus obtd.

Description

[Detailed Description of the Invention] Stop. The present invention relates to a method for manufacturing precipitation hardening alloy members that reduces residual stress caused by machining or deformation correction.

Modern pump shafts are made of Monel I (which has excellent corrosion resistance and strength).
500 (product name: same as Keisha) has begun to be used in place of stainless steel such as 8US804. Monel 500 is nickel copper alloy (JISH4553 NCuB) and AI (2
, 00-4.00%) and T i (0.2 5-1
．． 0 0%) and Ni3(Ti.

Al) is precipitated to improve the strength.

American Space Materials Standard (Aerospaca Mate)
real Spcci-ficaLion+s: IJ
(hereinafter referred to as AM8) is specified in Ah4S4676A. Figure 1 shows the conventional main process for manufacturing pump shafts using Monel I (500).The problem with this conventional method is that depending on the machining method, large bends may occur due to residual stress. #1: If the problem cannot be corrected by slight correction using a hammer or press, and the product must be discarded.

Furthermore, if a large bend is corrected using a hammer or press, residual stress will be generated during use, which may cause problems such as abnormal vibration corrosion during use. Therefore, in order to remove this residual stress, it is conceivable to perform a stress-removing annealing heat treatment after the bend 9 straightening B as shown in FIG.

However, 500 for Monel is the same as the above-mentioned Ni3 (AJ
Since it is a precipitation hardening material made of 7, Ti), the material quality changes by stress-relieving annealing heat treatment. Also AM84
The material properties specified in 676A are materials that have been subjected to a combination of annealing heat treatment and aging heat treatment, but when stress-relieving annealing heat treatment is added, the material changes in quality, and there is a problem that it cannot be recognized as heat treatment according to the standard. There is a point.

The present invention has been made in view of the above-mentioned problems of the conventional manufacturing method. 1. A precipitation hardening alloy member that is free from deformation and residual stress caused by machining or aging treatment, and can satisfy heat treatment standards for the material. The purpose is to provide a manufacturing method for.

That is, one aspect of the present invention is to divide the above aging treatment step into a plurality of steps in a method for producing a precipitation hardening alloy part, which includes one aging treatment step and a machining step or straightening step, and The above gist is a method for manufacturing a precipitation-hardened alloy component, characterized in that at least one of a machining step and a straightening step is performed between treatment steps.

With this configuration, the residual stress caused by straightening after the second machining can be removed by the second and subsequent aging treatment steps,
Moreover, since there is no need to perform a stress-relieving annealing process from time to time, there is no deterioration of the two members, and the heat treatment process itself can satisfy conventional standards as is.

The present invention will be explained below based on the embodiment shown in the process diagram of FIG.

First, dissolve the raw materials to form Monel with the chemical components listed in Table 1.
0 is cast into a block and forged into a diameter of 150mm and a length of 5mt.
Then, an annealing heat treatment was performed at 760°C x 0.51 + water cooling. Since it was bent, straightening A was performed using a cold press. Next, at the same temperature as before, 595℃
81+Aging heat treatment A of air cooling was performed. This aging heat treatment was carried out for only half the time specified in AM84676A regulations. Then machined to a diameter of 10
Processed to 0mm.

Correction B was performed again. Next, aging heat treatment B is performed under the same conditions as aging heat treatment A to complete the product. In other words, in this example, conventionally it was carried out at -1 degree/ζ4 aging heat treatment 2
It is divided into two parts, and machining and straightening are performed between these two aging heat treatments.

Residual stress caused by machining and straightening was removed by subsequent aging heat treatment B.

Since almost no residual stress remains in the 4A system, the displacement is small even after a long period of time, and in order to remove such residual stress, aging heat treatment and aging heat treatment performed before machining are added to the conventional heat treatment conditions. Since they are the same, the same quality of microorganisms can be obtained.

Table 2 shows the curve of this example and the conventional example shown in FIG. 1, which was conducted under the same heat treatment conditions as this example, and the H-year conversion by 1yj. Immediately after manufacturing, straightening, etc. were performed to approximately the same degree of 4'+'j, so the bending δ was the same. It can be seen that in the conventional example, the deformation is more than twice as large as that immediately after manufacture, even though the deformation is kept to a certain degree.

Here, one bend δ is a length of 5 as shown in the schematic diagram in Figure 4.
Refers to the maximum displacement of shaft 1 when rotating while supporting both ends of shaft 1 of m.

Oka 1 In this embodiment, the aging heat treatment is divided into two parts, but if the deformation caused by the second aging heat treatment is large, the first aging heat treatment and straightening may be performed in three or more parts. In addition, in this example, the aging heat treatment conditions were completely divided into two from the conventional aging heat treatment conditions, and the multiple aging heat treatment conditions were exactly the same. good. Further, in this embodiment, machining and straightening were performed simultaneously between the two aging heat treatments, but either one may be used depending on the degree of displacement during one aging treatment process.

Table 1 Chemical composition Table 2 Change in bending (δ) over time - 1 According to the method of the present invention, there is no residual stress, there is no bending or its change over time, and the quality of the moon (fl
It is possible to obtain a material with a high fi-

[Brief explanation of drawings]

Figures 1 and 2 show the conventional precipitation hardening type manufacturing process I.
Figures 1 and 3 are manufacturing process diagrams according to embodiments of the present invention, and Figure 4 is an explanatory diagram of the axis of the members.

Claims (1)

[Claims] Invention 1: The aging treatment step is divided into a plurality of steps, and the machining step and A method for manufacturing precipitation hardening alloy parts, which conventionally includes performing at least one of the straightening steps.