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Martensitic stainless steel capable of resisting occlusal wear

A martensitic stainless steel, occlusal wear technology, applied in the field of martensitic stainless steel and stainless steel, can solve the problems of occlusal jamming, increase process complexity and production cost, peeling of wear debris layer, etc., to prevent friction occlusion wear, excellent Machinability, the effect of reducing the tendency of weld cracking

Inactive Publication Date: 2012-10-31
POWERCHINA SPEM CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] In the field of power plant boiler feed water pumps and other pumps, the wear ring and the bushing are easily corroded due to contact with the water medium. The material is generally martensitic stainless steel, and the gap between the friction pairs is very small. When the pump starts and stops during the idling period, the pump rotor will have a greater deflection than that during normal operation, and sliding friction is prone to occur between the friction pairs. During friction, the temperature rises, the wear debris peels off in layers, and the friction pairs are prone to adhesive wear, until the bite is stuck, which will adversely affect the safe operation of the power plant and greatly increase the maintenance cost
[0003] At present, in order to prevent the occlusal wear of the friction pair, various surface treatment technologies are used to improve the friction and lubricity of the metal surface, such as sulfurization, phosphating, chlorination, soft metal film on the surface, etc., but these processes require the original metal material Secondary processing on the surface increases the complexity of the process and production costs, and is also prone to new problems
The German KSB company uses a stainless steel material code-named RWA350 to prevent the friction of the friction pair from sticking and occluding, but the weld seam of this material is very easy to crack after welding, which limits its application range
[0004] Chinese Patent Publication No. CN201090500, the publication date is July 23, 2008. In the patent document named "Wearing Ring of Feed Water Pump", the inner surface of the wearing ring is processed into a honeycomb surface to avoid the occlusion of the water pump rotor. However, this kind of wear ring is complicated to process and the manufacturing cost is high

Method used

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  • Martensitic stainless steel capable of resisting occlusal wear
  • Martensitic stainless steel capable of resisting occlusal wear
  • Martensitic stainless steel capable of resisting occlusal wear

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] Composition (weight%) C: 0.10-0.16%, Si: 0.10-1.00%, Mn: 1.20-1.60%, Cr: 12.00-14.00%, Mo: 0.40-0.60%, Ni: 0.10-0.60%, P≤0.035 %, S: 0.24-0.32%, and the rest are Fe and unavoidable impurity elements.

[0049] Design raw material ingredients according to the above ingredients, smelt in an induction furnace, bake and dehumidify the raw materials and then load them in order: pure iron, scrap steel, nickel plate, ferrochromium, ferromolybdenum, ferromanganese and silicon calcium powder 10 minutes before tapping, Add iron sulfur 1 minute before tapping.

[0050] The composition of the martensitic stainless steel (code name: SP11) designed and prepared above to prevent occlusal wear was tested, and the test report is as follows:

[0051] Component test results:

[0052] C: 0.14%, Si: 0.51%, Mn: 1.35%, Cr: 13.08%, Mo: 0.49%, Ni: 0.25%, P: 0.024%, S: 0.273%, and the rest are Fe and unavoidable impurity elements.

[0053] The above pouring material is heat treated, the proces...

Embodiment 2

[0063] A martensitic stainless steel with anti-occlusion wear, its main components are (weight%): C: 0.14%, Si: 0.45%, Mn: 1.37%, Cr: 13.12%, Mo: 0.47%, Ni: 0.27%, P: 0.026%, S: 0.278%, and the rest are Fe and unavoidable impurity elements. made as figure 1 Wear ring 2 shown, the steel of the present invention (code name: SP11) and 17-4PH are carried out friction contrast test, as figure 1 As shown, the wear ring 2 is assembled with the impeller 1, the wear ring 1 is fixed, the gap between the wear ring 2 and the impeller 1 is adjusted to make them in close contact (the radial clearance is 0), and pressure is applied (the weight of the impeller 1 and the impeller shaft 3 ), apply the same torque to one end of the impeller shaft 3 to rotate the impeller 1, so that the impeller 1 starts to rotate and produces sliding friction with the wear ring 2, and the wear ring 2 made of 17-4PH material will stick and bite within three minutes after the impeller 1 rotates In the case of be...

Embodiment 3

[0067] A martensitic stainless steel with anti-occlusion wear, its main components are (weight%): C: 0.14%, Si: 0.45%, Mn: 1.37%, Cr: 13.12%, Mo: 0.47%, Ni: 0.27%, P: 0.026%, S: 0.278%, and the rest are Fe and unavoidable impurity elements. Such as figure 2 As shown, the welding plate 4 is made of 2Cr13 material. After preheating the two welding plates at 250°C, use A507 (GB / T983 E16-25MoN-15) welding rod to weld the grooves on both sides. The interlayer temperature is less than 300°C. Then slowly cool to room temperature, and then spot weld two spots evenly in the middle of the welding plate without preheating. The length of the spot is about 20mm and the height is about 5mm. No cracks appeared in solder joint 5 after room temperature.

[0068] Repeat the above test with the welding plate made of RWA350, and cracks appear in the solder joints during the cooling process after spot welding.

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Abstract

The invention relates to a martensitic stainless steel capable of resisting occlusal wear, belonging to the field of metal materials. The martensitic stainless steel contains the following components by weight percent: 0.10-0.16% of C, 0.10-1.00% of Si, 1.20-1.60% of Mn, 12.00-14.00% of Cr, 0.40-0.60% of Mo, 0.10-0.60% of Ni, not more than 0.035% of P, 0.24-0.32% of S and the balance of Fe and inevitable impurities. The martensitic stainless steel provided by the invention has the advantages of reasonable formula design, high hardness, good friction lubrication, low welding cracking tendency and low production cost, and is capable of preventing occlusal wear.

Description

technical field [0001] The invention relates to a stainless steel, in particular to a martensitic stainless steel with anti-occlusion wear, which belongs to the field of metal materials. Background technique [0002] In the field of power plant boiler feed water pumps and other pumps, the wear ring and the bushing are easily corroded due to contact with the water medium. The material is generally martensitic stainless steel, and the gap between the friction pairs is very small. When the pump starts and stops during the idling period, the pump rotor will have a greater deflection than that during normal operation, and sliding friction is prone to occur between the friction pairs. During friction, the temperature rises, the wear debris peels off in layers, and adhesive wear is likely to occur between the friction pairs, until the bite is stuck, which will adversely affect the safe operation of the power plant and greatly increase the maintenance cost. [0003] At present, in ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/60C21C5/52
CPCY02P10/20
Inventor 吕建南郑昱马莉郑骏孙伟忠吴宝鑫成晓伟
Owner POWERCHINA SPEM CO LTD