Nickel-based brazing filler metal for oil cooler quickly brazed in low vacuum condition

Abstract

The invention relates to a nickel-based brazing filler metal for an oil cooler quickly brazed in a low vacuum condition. The nickel-based brazing filler metal comprises the following chemical components in percentage by weight: 28.0-30.0% of Cr, 5.0-7.0% of P, 3.5-4.5% of Si, 0.3-0.5% of Mn, 0.1-0.2% of Ti, 2.0-5.0% of Fe, 0-0.2% of sum of impurity elements S, O and N, 0-0.2% of C and the balanceof Ni. By adding ferrochromium powder, resistance to oxidation of an alloy in the low vacuum condition can be improved, so that a blackening problem is solved; by adding titanium and manganese, traceoxygen can be removed in the low vacuum condition, so that the wetting spreadability property of the brazing filler metal on stainless steel is improved. The novel nickel-based paste brazing filler metal has a relatively good flowing property, is moderate in cost, meets the demand on strength, and has good corrosion resistance.

Description

technical field [0001] The invention relates to the field of welding, in particular to a nickel-based brazing filler metal for rapid brazing of an oil cooler under low vacuum conditions. Background technique [0002] With the continuous upgrading of emission regulations, the requirements of the engine are also constantly increasing. The oil temperature of the engine lubrication system is getting higher and higher, even as high as 150°C, and the role of the oil cooler is increasing. At present, most stainless steel oil cooler products are welded with pure copper solder. During use, it is found that high-temperature engine oil continuously scours the copper in the channel of the oil cooler to cause copper corrosion. affect its performance. [0003] At present, domestic and international customers such as Sinotruk, Xichai, Cummins, Caterpillar, and Perkins have clearly put forward the demand for low-copper stainless steel oil coolers. The common welding method for oil cooler...

AI Technical Summary

Problems solved by technology

If the current welding process is not changed, but the traditional copper solder is directly switched to nickel-based solder, the problem is that the nickel-based solder will be oxidized, resulting in blackening of the surface

If all the low vacuum is transformed into a high vacuum, the cost will increase more, and the high vacuum brazing furnace has extremely high requirements on the vacuum degree. If it is used for a long time, the volatile matter in the brazing material will form oily residue on the furnace wall. Contaminate the atmosphere of the furnace, resulting in a substantial increase in the later use and maintenance costs of the vacuum furnace