阅读说明：本技术 提高低速船用柴油机白合金堆焊结合性能的方法 (Method for improving white alloy surfacing bonding performance of low-speed marine diesel engine ) 是由 崔新全 李东超 刘忠 刘征 于 2019-10-21 设计创作，主要内容包括：提高低速船用柴油机白合金堆焊结合性能的方法,该方法通过对待堆焊白合金表面加工后喷砂,然后使用化学方法除锈后涂氯化锌焊液进行镀锡,时效后打磨镀锡表面去除氧化物,最后进行白合金堆焊。最好是选用短路过渡熔化极氩弧焊基础上,增加焊丝回抽动作帮助熔滴脱落的白合金堆焊,熔滴短路时电流电压几乎为零,达到堆焊可靠并节能的作用和效果。采用钢丸和钢丝段对加工后表面进行喷砂除锈并形成表面粗糙度,这样增加有效面积,进而提高白合金与工件的绝对结合强度。用化学方式除锈,涂刷焊液进行热侵镀镀锡,保证镀锡层和工件的过渡层并没脆性物生成。(The method for improving the surfacing bonding performance of the white alloy of the low-speed marine diesel engine comprises the steps of processing the surface of the white alloy to be surfaced, then carrying out sand blasting, then carrying out rust removal by using a chemical method, then coating zinc chloride welding solution for carrying out tin plating, carrying out aging, then polishing the tin-plated surface to remove oxides, and finally carrying out white alloy surfacing. On the basis of short-circuit transition consumable electrode argon arc welding, the white alloy surfacing welding which is added with the drawing back action of the welding wire to help the molten drop to fall off is preferably selected, the current and voltage are almost zero when the molten drop is in short circuit, and the effects and effects of reliable surfacing welding and energy saving are achieved. And the processed surface is subjected to sand blasting and rust removal by adopting steel shots and steel wire sections, and the surface roughness is formed, so that the effective area is increased, and the absolute bonding strength of the white alloy and the workpiece is further improved. Derusting by a chemical mode, and coating a welding liquid to perform hot-dip plating and tinning so as to ensure that a tinning layer and a transition layer of a workpiece are not generated with fragile substances.)

1. The method for improving the white alloy surfacing bonding performance of the low-speed marine diesel engine is to perform surface pretreatment before the white alloy surfacing of the low-speed marine diesel engine, and is characterized in that: after the surface of a white alloy workpiece of a low-speed marine diesel engine is processed, sand blasting is carried out on the surface of the white alloy workpiece to be built up, then rust removal is carried out by using a chemical method, zinc chloride welding liquid is coated for tin plating, after aging, the tin-plated surface is polished to remove oxides, and finally white alloy build-up welding is carried out.

2. The method for improving the white alloy surfacing welding bonding performance of the low-speed marine diesel engine according to claim 1, is characterized in that: and (3) carrying out sand blasting on the surface before tinning, wherein the sand blasting grade reaches Sa 2.5, and the surface roughness is 30-80 mu m.

3. The method for improving the white alloy surfacing welding bonding performance of the low-speed marine diesel engine according to claim 1 or 2, is characterized in that: and on the basis of selecting short-circuit transition consumable electrode argon arc welding for white alloy surfacing, the white alloy surfacing with the welding wire drawing back action to help molten drops to fall off is added.

Technical Field

The invention relates to a method for improving the surfacing bonding performance of white alloy of a low-speed marine diesel engine.

Background

White alloy is a popular name for tin-based sliding bearing alloy, or babbitt metal. The white alloy has good comprehensive mechanical properties such as wear resistance, small linear expansion coefficient, corrosion resistance and the like, and is widely applied to key parts such as sliding blocks, thrust blocks, thin-wall tiles, crosshead bearings and the like in low-speed marine diesel engines. The traditional production mode is casting molding, the quality is unstable, the labor intensity is high, and the environmental pollution is serious. In recent years, the transition from casting to build-up welding is gradually carried out, and compared with the casting method, the build-up welding method has the advantages that the labor intensity is greatly reduced, and the environment is protected. However, the bonding performance of the white alloy subjected to surfacing welding is unstable, more iron-containing brittle compounds exist in the bonding layer, the absolute bonding strength index is unqualified, the thickness of the bonding layer is too thick, and the like.

Disclosure of Invention

The invention provides a method for improving the white alloy surfacing bonding performance of a low-speed marine diesel engine aiming at the problem of white alloy surfacing. On the basis of short-circuit transition consumable electrode argon arc welding, the white alloy surfacing welding which is added with the drawing back action of the welding wire to help the molten drop to fall off is preferably selected, the current and voltage are almost zero when the molten drop is in short circuit, and the effects and effects of reliable surfacing welding and energy saving are achieved.

The processing surface in the method is subjected to sand blasting, and the processed surface is subjected to sand blasting by adopting steel shots and steel wire sections with Rockwell hardness in the range of HRC45-50, wherein the Sa 2.5 is achieved, and the surface roughness is 30-80 mu m, so that the effective area is increased as much as possible in unit area, the bonding area of the white alloy and the workpiece is increased, and the absolute bonding strength of the white alloy and the workpiece is further improved.

In the tin plating in the method, industrial hydrochloric acid is adopted to remove rust on the surface after sand blasting, then saturated zinc chloride welding solution is coated, hot-dip plating tin plating is carried out at the temperature of 280-300 ℃, the tin plating time is not more than 45 minutes, so that the thickness of a tin plating layer and the thickness of a transition layer of a workpiece can be effectively ensured to be in a proper range, the thickness of the transition layer of overlaying welding after tin plating and non-tin-plating overlaying welding can be reduced by more than 50 percent through detection calculation comparison, the generation amount of FeSn and FeSn2 brittle compounds in the transition layer is greatly reduced, the absolute bonding strength of the white alloy and the workpiece is further improved, and the amplitude is improved by about 20 percent.

Drawings

FIG. 1 is a schematic view of tin plating according to the present invention.

Detailed Description

The invention discloses a method for improving the surfacing bonding performance of white alloy of a low-speed marine diesel engine, which comprises the steps of processing the surface of a workpiece to be surfaced with white alloy (3), then carrying out sand blasting, then removing rust on the surface of the workpiece to be surfaced with the white alloy by using a chemical reaction method, hoisting by using a rope (1), coating zinc chloride welding solution, and then carrying out tinning (2). And after tinning and aging, polishing the tinned surface to remove oxides, and finally performing white alloy surfacing. On the basis of short-circuit transition consumable electrode argon arc welding, welding wire drawing back action is added to assist white alloy surfacing with molten drop dropping, current and voltage are almost zero when molten drops are in short circuit, and the effects and effects of reliable surfacing and energy saving are achieved. The surface of a workpiece to be subjected to surfacing welding white alloy is subjected to machining surface sand blasting, the machined surface is subjected to sand blasting by adopting steel shots and steel wire sections with Rockwell hardness within the range of HRC45-50, Sa 2.5 is achieved, and the surface roughness reaches 30-80 mu m, so that the effective area is increased as much as possible in a unit area, the bonding area of the white alloy and the workpiece is increased, and the absolute bonding strength of the white alloy and the workpiece is further improved. And before tinning, derusting the surface after sand blasting by using industrial hydrochloric acid, then coating saturated zinc chloride welding solution, hoisting by using a rope sling (1), and then carrying out hot-dip tinning (2) at the temperature of 280-300 ℃, wherein the tinning time is not more than 45 minutes. Therefore, the thickness of the transition layer of the tinned layer and the transition layer of the workpiece can be effectively ensured to be in a proper range, the thickness of the transition layer of the tin-plated surfacing and the non-tin-plated surfacing can be reduced by more than 50% through detection, calculation and comparison, and the generation amount of FeSn and FeSn2 brittle compounds in the transition layer can be greatly reduced, so that the absolute bonding strength of the white alloy and the workpiece is improved, and the amplitude is improved by about 20%.