CN-122016899-A - Inspection method for G115 martensitic heat-resistant steel pipe

CN122016899ACN 122016899 ACN122016899 ACN 122016899ACN-122016899-A

Abstract

The application provides an inspection method for a G115 martensitic heat-resistant steel pipe, which comprises the following steps of preparing a to-be-inspected sample of the to-be-inspected steel pipe, carrying out optical mirror observation on the to-be-inspected sample, determining a target inspection area of the to-be-inspected sample, wherein the target inspection area is an area where a tungsten-rich phase is located, determining an optical mirror inspection standard and an electron mirror inspection standard corresponding to a smelting mode according to the smelting mode of the to-be-inspected steel pipe, determining a primary inspection result of the to-be-inspected steel pipe according to first metallographic information and the optical mirror inspection standard in the target inspection area, carrying out electron mirror observation on the target inspection area if the primary inspection result is qualified, and determining an inspection result of the to-be-inspected steel pipe according to second metallographic information and the electron mirror inspection standard in the target inspection area. The inspection method provided by the application can realize the targeted and systematic judgment of the qualification of the steel pipe, avoid the potential failure risk caused by the abnormal tungsten-rich phase, effectively detect the steel pipe with defects and improve the inspection accuracy.

Inventors

LIANG JINMING
MA ZHIBAO
GUO DERUI
CHEN XIN
TU GA
LI SUIFU
WANG CHUNZHONG
SUN DEJIN
LI ZHAOYING
JIANG HAIFENG
CHENG WEI
WANG QINGFENG
LI WEILI

Assignees

大唐郓城发电有限公司
中国大唐集团科学技术研究总院有限公司
中国大唐集团科学技术研究总院有限公司华北电力试验研究院

Dates

Publication Date: 20260512
Application Date: 20260127

Claims (10)

1. The inspection method for the G115 martensitic heat-resistant steel pipe is characterized by comprising the following steps of: preparing a sample to be inspected of the steel pipe to be inspected; Performing optical lens observation on the sample to be detected, and determining a target detection area of the sample to be detected, wherein the target detection area is an area where a tungsten-rich phase is located; determining an optical lens inspection standard and an electron lens inspection standard corresponding to the smelting mode according to the smelting mode of the steel pipe to be inspected; determining a primary inspection result of the steel pipe to be inspected according to the first metallographic information in the target inspection area and the optical lens inspection standard; if the primary detection result is qualified, performing electron microscope observation on the target detection area; and determining the inspection result of the steel pipe to be inspected according to the second metallographic information in the target inspection area and the electron microscope inspection standard.
2. The method according to claim 1, wherein the smelting mode comprises electroslag smelting and non-electroslag smelting.
3. The method of inspection according to claim 2, wherein, The determining the primary inspection result of the steel pipe to be inspected according to the first metallographic information in the target inspection area and the optical inspection standard specifically comprises the following steps: acquiring first metallographic information in the target inspection area, wherein the first metallographic information comprises the distribution form of a tungsten-rich phase under observation of a light microscope; when the distribution form is discrete distribution, determining that the primary detection result of the steel pipe to be detected is qualified, wherein the discrete distribution means that a plurality of tungsten-rich phase particles are independently distributed; when the distribution form is cluster distribution, determining a primary detection result of the steel pipe to be detected according to the number of clusters, the cluster length and a first light mirror detection standard; and when the distribution form is intermittent distribution along the grain boundary or continuous distribution, determining the primary detection result of the steel pipe to be detected according to the distribution length and the second optical lens detection standard.
4. The method of inspection according to claim 3, wherein, The first optical lens inspection standard comprises the number of clusters which is less than or equal to X and the cluster length which is less than or equal to Y mu m; the second optical lens inspection standard comprises that the distribution length is less than or equal to Q mu m; when the smelting mode of the steel pipe to be detected is electroslag smelting, X=1, Y=80 and Q=40; When the smelting mode of the steel tube to be detected is non-electroslag smelting, X=3, Y=150 and Q=50.
5. The method of inspection according to claim 2, wherein, The step of determining the test result of the steel pipe to be tested according to the second metallographic information in the target test area and the electron microscope test standard specifically comprises the following steps: Acquiring second metallographic information in the target inspection area, wherein the second metallographic information comprises the distribution form of a tungsten-rich phase under electron microscope observation; When the distribution form is discrete distribution or cluster distribution, determining the test result of the steel pipe to be tested according to the tungsten-rich phase particle size and a first electron microscope test standard; and when the distribution form is intermittent distribution or continuous distribution along the grain boundary, determining the test result of the steel pipe to be tested according to the distribution length and the second electron microscope test standard.
6. The method of inspection according to claim 5, wherein, The first electron microscope inspection standard comprises that the particle size of the tungsten-rich phase is less than or equal to F mu m, and the number of the tungsten-rich phase particles with the size of E mu m-F mu m is less than or equal to 30 percent; the second electron microscope inspection standard comprises that the distribution length is less than or equal to Q mu m; when the smelting mode of the steel pipe to be detected is electroslag smelting, E= 2,F =3 and Q=40; when the smelting mode of the steel tube to be detected is non-electroslag smelting, e= 2,F =5 and q=50.
7. The method according to claim 1, wherein preparing the sample of the steel pipe to be inspected comprises: Taking at least two samples from the steel pipe to be detected; and preprocessing the test surface of the test sample to obtain the test sample of the steel pipe to be tested.
8. The method according to claim 7, wherein the test surface of the test specimen is a plane parallel to the radial surface of the steel pipe to be inspected.
9. The method according to claim 7, wherein one of the at least two samples is taken from an inner wall of one end of the steel pipe to be inspected.
10. The method of inspection according to claim 7, wherein the pretreatment comprises grinding, polishing and etching sequentially.

Description

Inspection method for G115 martensitic heat-resistant steel pipe Technical Field The application relates to the technical field of metal material inspection, in particular to an inspection method for a G115 martensitic heat-resistant steel pipe. Background G115 The (08 Cr9W3Co3 VNbCuBN) steel is a new generation martensitic heat-resistant steel, and is widely applied to high-temperature components of a supercritical power station boiler, such as large-caliber thick-wall steel pipes, due to the excellent high-temperature durability, creep resistance and structural stability. In G115 steel, tungsten (W) is an important solid solution strengthening and precipitation strengthening element, but it may form a tungsten-rich phase during solidification and subsequent heat treatment, such as Laves et al. The size, shape, distribution and quantity of the tungsten-rich phases have remarkable influence on the mechanical properties, particularly toughness and durability, of the steel, so that the creep property and long-term service safety of the steel pipe are further influenced. At present, the inspection of the G115 steel pipe depends on the existing standards such as T/CSTM 00017, Q/OAPD 2253 and the like, and only conventional mechanical properties and tissue inspection are covered, so that the inspection of the G115 steel pipe is carried out by means of the existing standards, even if the conventional mechanical properties of the steel pipe are qualified, tungsten-rich abnormal distribution can still exist in the steel pipe, and the defect pipe which is qualified in conventional properties and abnormal in tungsten-rich phase cannot be effectively screened out by the prior art, so that the potential failure risk of the G115 steel pipe exists. Disclosure of Invention In order to solve the problems in the prior art, the application provides a test method for a G115 martensitic heat-resistant steel pipe. The technical problems to be solved by the application are realized by the following technical scheme: The application provides a method for inspecting a G115 martensitic heat-resistant steel pipe, which comprises the following steps: preparing a sample to be inspected of the steel pipe to be inspected; Carrying out optical observation on a sample to be detected, and determining a target detection area of the sample to be detected, wherein the target detection area is an area where a tungsten-rich phase is located; Determining an optical lens inspection standard and an electron lens inspection standard corresponding to the smelting mode according to the smelting mode of the steel pipe to be inspected; Determining a primary inspection result of the steel pipe to be inspected according to the first metallographic information and the optical lens inspection standard in the target inspection area; If the primary detection result is qualified, performing electron microscope observation on the target detection area; and determining the inspection result of the steel pipe to be inspected according to the second metallographic information in the target inspection area and the electron microscope inspection standard. In one implementation, the smelting mode comprises electroslag smelting and non-electroslag smelting. In one implementation manner, determining the primary inspection result of the steel pipe to be inspected according to the first metallographic information and the optical lens inspection standard in the target inspection area specifically comprises: acquiring first metallographic information in a target inspection area, wherein the first metallographic information comprises the distribution form of a tungsten-rich phase under light microscope observation; When the distribution form is discrete distribution, determining that the primary detection result of the steel pipe to be detected is qualified, wherein the discrete distribution means that a plurality of tungsten-rich phase particles are independently distributed; when the distribution form is cluster distribution, determining a primary detection result of the steel pipe to be detected according to the number of clusters, the cluster length and a first light mirror detection standard; And when the distribution form is intermittently distributed along the grain boundary or is intermittently distributed, determining the primary detection result of the steel pipe to be detected according to the distribution length and the second optical lens detection standard. In one implementation, the first optical inspection criteria includes a number of clusters of X or less and a cluster length of Y μm or less; the second optical lens inspection standard comprises that the distribution length is less than or equal to Q mu m; when the smelting mode of the steel pipe to be detected is electroslag smelting, X=1, Y=80 and Q=40; When the smelting mode of the steel pipe to be detected is non-electroslag smelting, X=3, Y=150 and Q=50. In one implementation manner, determining the