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Detection method of low-carbon alloy steel abnormal phase

A low-carbon alloy steel and detection method technology, applied in the preparation of test samples, material magnetic variables, etc., can solve problems such as high cost, interference of corrosive agents and corrosion effects, and inability to determine abnormal phase types, and achieve simple operation and ease Observation, low cost effect

Active Publication Date: 2018-01-16
AEROSPACE PRECISION PROD INC LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] The above three detection methods are routine detection methods for the microstructure of materials, but as a detection method for the carburization of fastener products, there are certain deficiencies: the first metallographic detection method is simple and easy to implement, but the observation of abnormal structures Interferenced by corrosive agents and corrosion effects, and the type of abnormal phase cannot be determined (usually ferrite and austenite cannot be distinguished); the second and third detection methods require the use of scanning electron microscopy or X-ray diffraction instruments, general fasteners The enterprise does not have the testing capability, and the outsourcing testing time is out of control and the cost is high

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  • Detection method of low-carbon alloy steel abnormal phase

Examples

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Embodiment approach 1

[0020] 0Cr17Ni4Cu4Nb martensitic precipitation hardening stainless steel MJ4 threaded bolts after heat treatment detection of abnormal phase layer depth and phase category.

[0021] The raw material specifications of 0Cr17Ni4Cu4Nb used to manufacture MJ4 threaded bolts are Take straightened 0Cr17Ni4Cu4Nb material to make long L 0 = 5 test rods of 50mm, numbered N 1 , N 2 , N 3 , N 4 , N 5 , cut a depth P on each test bar by wire cutting 1 =0.1mm, P 2 =0.2mm, P 3 =0.3mm, P 4 =0.4mm, P 5 = 0.5mm axial long groove, the bottom surface of the groove is respectively in the diameter of the truncated circle (d-2P i ) on the outer circle of the cylinder, that is, N 1 ~N 5 The radius of curvature of the arc at the bottom of the test bar is 1.85mm, 1.75mm, 1.65mm, 1.55mm, and 1.45mm respectively, and the radial projection surface of the arc bottom of the long groove is rectangular, and the length and width are 50mm and 1mm respectively. Put the test rod and the product in t...

Embodiment approach 2

[0023] Abnormal phase layer depth and phase type detection of Cr16Ni6 stainless steel ear bolts of a certain type of aircraft engine after heat treatment.

[0024]The specification of the Cr16Ni6 stainless steel bar stock used to manufacture ear bolts is φ45mm, and the bar stock was cut to make 5 test bars with length L0=60mm, numbered respectively N1, N2, N3, N4, N5, and the wire cutting method was used in each test bar. Cut a long axial groove with a depth of P1=0.2mm, P2=0.35mm, P3=0.5mm, P4=0.65mm, P5=0.8mm on the rod, and the bottom surface of the groove is respectively in the truncated circle with a diameter of (d-2Pi) On the outer circular surface of the cylinder, that is, the radius of curvature of the bottom surface of the N1~N5 test rods is 22.3mm, 22.15mm, 22mm, 21.85mm, and 21.7mm respectively, and the radial projection surface of the bottom surface of the long groove arc is rectangular, and the length , width are 60mm, 1mm respectively. Quenching (1.5h at 1000°C,...

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Abstract

The invention provides a detection method of a low-carbon alloy steel abnormal phase, wherein the detection method comprises the following steps: N cylindrical test rods having the same material and production specifications as those of a product are adopted, wherein the diameter of the rods is d and the length is L0; the surface of each test rod Ni is provided with a long groove arranged in an axial direction and having the depth of Pi, the groove depth of each long groove increases or decreases progressively, and the groove length of each long groove is L1; the bottom surface of each long groove is on the outer circle surface of a cylinder having the cross-sectional diameter of d-2Pi and being coaxial with the test rods; the test rods and the product are subjected to heat treatment in asame furnace; after heat treatment, the test rods are ground coaxially to the diameter of d-2Pi, and at the moment, the groove bottom of each long groove is on the cylindrical surface of a new cylinder after grinding; and the test rods are energized and are circumferentially magnetized, all the test rods Ni are detected one by one by a magnetic powder, and whether magnetic leakage exists is judged. The method makes up for the defects that the metallographic examination is susceptible to interference and the type of the abnormal phase cannot be accurately judged. The method is simple and the cost is low.

Description

technical field [0001] The invention relates to a detection method of a low-carbon alloy steel phase, in particular to a detection method of an abnormal phase of a low-carbon alloy steel after heat treatment and carburization. Background technique [0002] With the increasing demand for high-performance fastener applications in aerospace and other types of equipment, the demand for the use of excellent fastener manufacturing materials has become increasingly prominent. Because high carbon content will lead to the weakening of alloy corrosion resistance, the traditional method of strengthening alloys by increasing carbon content has been gradually replaced by other strengthening methods. Alloy steel materials for fasteners are developing in the direction of low carbon, corrosion resistance and high strength. . Driven by the market demand for high-performance fasteners, a number of excellent low-carbon alloy steel materials such as 0Cr17Ni4Cu4Nb, 0Cr16Ni6, 0Cr17Ni7Al, 0Cr15Ni...

Claims

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Application Information

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IPC IPC(8): G01N27/84G01N1/28G01N1/44
Inventor 柳思成高云余传魁康彪王川郭双双王葑
Owner AEROSPACE PRECISION PROD INC LTD