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CN-116921808-B - Surfacing method of sealing surface of valve of internal combustion engine and valve of internal combustion engine

CN116921808BCN 116921808 BCN116921808 BCN 116921808BCN-116921808-B

Abstract

The invention relates to a build-up welding method of a sealing surface of an internal combustion engine valve and the internal combustion engine valve. The surfacing method of the valve sealing surface of the internal combustion engine comprises the following steps of preheating a valve blank to 100-200 ℃, fixing, starting arc starting at any point of a welding gun near the outer circle of a disc of a welding groove, starting arc quenching after welding for 360 degrees, forming a first alloy layer, performing surfacing for the second time, starting arc after moving the welding gun for 2-3 mm towards the valve neck at the surfacing position of the first layer, starting arc quenching after welding for 365 degrees, and forming a second alloy layer. The invention also provides an internal combustion engine valve, and the build-up welding of the sealing surface of the internal combustion engine valve is obtained by adopting the build-up welding method. The invention effectively improves the uniformity of the thickness of the surfacing alloy layer and reduces the risks of cracking, failure and the like in the use process caused by uneven stress distribution.

Inventors

  • WANG TAO
  • DING MANPING
  • CHEN MINGJIAN
  • ZHANG GUANGCHUAN
  • LUO XIAOFEI

Assignees

  • 重庆跃进机械厂有限公司

Dates

Publication Date
20260508
Application Date
20230830

Claims (7)

  1. 1. A method of surfacing a valve sealing surface of an internal combustion engine, comprising the steps of: S1, pre-treating, namely preheating a valve blank to 100-200 ℃; S2, performing primary surfacing, namely enabling a welding gun to perform arc starting at any point of a welding groove near the outer circle of the disc, and welding for 360 degrees to form a first alloy layer, wherein the welding speed of the primary surfacing is 0.7-0.8 rpm, and the welding current is 115-120A; S3, performing secondary build-up welding, namely moving a welding gun to the direction of the valve neck at the first build-up welding position for 2-3mm, then striking an arc, welding for 365 degrees, so that the overlap ratio of the second alloy layer and the first alloy layer is more than or equal to 50%, forming a second alloy layer, wherein the welding speed of the secondary build-up welding is 0.5-0.7 rpm, and the welding current is 105-115A.
  2. 2. The method for overlaying a valve sealing surface of an internal combustion engine according to claim 1, wherein the alloy components of the first alloy layer and the second alloy layer comprise, by mass, 1.10 to 1.70% of carbon, 26.0 to 33.0% of chromium, 1.0% of molybdenum, 0.40 to 2.00% of silicon, 3.0% of nickel, 7.0 to 9.50% of tungsten, 3.0% of iron, 0.03% of sulfur, 0.03% of phosphorus, 0.03% of oxygen, 0.1% of manganese, and the balance cobalt, or comprise 1.10 to 1.70% of carbon, 28.0 to 30.0% of chromium, 1.0% or less than 1.50% of molybdenum, 3.0% of silicon, 3.5 to 5.5% of tungsten, 3.0% of iron, 0.03% of sulfur, 0.03% of phosphorus, 0.03% of oxygen, 0.5% of manganese, and the balance cobalt.
  3. 3. The method for overlaying a valve sealing surface of an internal combustion engine according to claim 1, wherein in S2, the powder feeding amount for the first overlaying is 35% -40%.
  4. 4. The method for overlaying the valve sealing surface of the internal combustion engine according to claim 1, wherein in S3, the powder feeding amount of the second overlaying is 40% -45%.
  5. 5. The method for overlaying a valve sealing surface of an internal combustion engine according to claim 1, wherein in the step S1, the roughness of a valve blank weld groove is less than or equal to Ra1.6, the runout of a disk end surface to a valve rod is less than or equal to 0.1, and the roundness of the weld groove is less than or equal to 0.05.
  6. 6. The method of build-up welding a valve sealing surface of an internal combustion engine of claim 1, wherein the first and second alloy layers have a uniformity of 0.5mm or less.
  7. 7. An internal combustion engine valve, characterized in that the build-up welding of the sealing surface of the internal combustion engine valve is obtained by a build-up welding method according to any one of claims 1 to 6.

Description

Surfacing method of sealing surface of valve of internal combustion engine and valve of internal combustion engine Technical Field The invention relates to the technical field of manufacturing of internal combustion engines, in particular to a build-up welding method of a sealing surface of an internal combustion engine valve and the internal combustion engine valve. Background The intake and exhaust valve seats used in high-speed diesel engines in high-power ships must have good impact resistance, corrosion resistance and wear resistance to withstand high-temperature corrosion, gas flushing and seating impact of the valves. In order to improve the wear resistance and corrosion resistance, a layer of wear-resistant and corrosion-resistant alloy is deposited on the sealing conical surface, however, as the alloy layer material is different from the base material, the linear expansion coefficient of the alloy is generally lower than that of the base material, and the expansion amount of the base material is higher than that of the deposited alloy layer at high temperature, so that a thermal hoop force is formed on the deposited alloy layer, namely tangential tensile stress is increased on the surface of the sealing conical surface, and if the thickness of the whole alloy layer is inconsistent and the uniformity is poor, the stress field distribution is inconsistent, and the stress release is easy to generate in the use process, so that the risk of cracking and failure exists. Disclosure of Invention The invention aims to provide a build-up welding method of a sealing surface of an internal combustion engine valve and the internal combustion engine valve, so as to improve the thickness uniformity of a build-up welding alloy layer and reduce risks of cracking, failure and the like in the use process caused by uneven stress distribution. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a method of surfacing a valve sealing surface of an internal combustion engine, comprising the steps of: s1, preprocessing, namely preheating a valve blank to 100-200 ℃ and then fixing; S2, performing primary surfacing, namely enabling a welding gun to start an arc at any point of the welding groove near the outer circle of the disc, properly adjusting welding current and welding speed according to the molten pool condition and the welding line forming condition, ensuring that the welding groove is just fully paved with alloy, and starting arc quenching after one circle of welding, namely 360 degrees, to form a first alloy layer; And S3, performing secondary build-up welding, namely moving a welding gun to the direction of the valve neck at the first layer build-up welding position for 2-3 mm, then striking an arc, properly adjusting and reducing the welding speed, increasing the powder feeding amount of the alloy, starting arc quenching after welding for 365 degrees, ensuring that the second layer of alloy can cover the first layer of alloy, and ensuring that the overlap ratio of the second layer of alloy layer and the first layer of alloy layer is more than or equal to 50 percent so as to ensure that the thickness dimension of the alloy meets the requirement, and forming the second layer of alloy layer. According to the technical means, the surfacing alloy is formed in the weld groove of the valve blank by adopting a plasma surfacing process in a manner of performing surfacing at least twice, the preheating temperature, the welding current and the welding speed are reasonably controlled, the uniformity of the thickness of a surfacing alloy layer is effectively ensured, the uniformity of the thickness of the surfacing alloy layer is improved, meanwhile, the welding arcing position is reasonably adjusted by surfacing twice, the alloy flow direction is controlled to ensure the roundness of the alloy welding, excessive melting of the base metal is avoided, the situation that the alloy just fills the edge of the weld groove is ensured, and the problem that the alloy deviates from the weld groove to cause local edge welding collapse is avoided, and the alloy layer and the base metal are made to be in a straight line, so that saw-shaped formation is avoided, the uniformity of the surfacing alloy layer is further effectively ensured, and the risks of cracking, failure and the like in the using process due to uneven stress distribution are effectively reduced. The alloy of the first alloy layer and the second alloy layer is Stellite 6# and Stellite12# series alloy, and the alloy composition of the first alloy layer and the second alloy layer comprises, by mass, 1.10-1.70% of carbon (C), 26.0-33.0% of chromium (Cr), 1.0% of molybdenum (Mo), 0.40-2.00% of silicon (Si), 3.0% of nickel (Ni), 7.0-9.50% of tungsten (W), 3.0% of iron (Fe), 0.03% of sulfur (S), 0.03% of phosphorus (P), 0.03% of oxygen (O), 0.1% of manganese (Mn), the balance cobalt (Co), or comprises 1.10-1.70% of carbon (C), 28.