CN102936643A - Novel quenching medium - Google Patents

Abstract

The invention discloses a novel quenching medium and relates to the technical field of quenching agents, the novel quenching medium is characterized by comprising the following components: 25 percent of sodium nitrate, 20 percent of sodium nitrite, 20 percent of potassium nitrate, 2 percent of polyvinyl alcohol, 3 percent of sodium chloride and 30 percent of water. The novel quenching medium can be used for replacing a water, oil, salt and alkaline multi-medium quenching agent, and is high in cooling capacity in low temperature, medium temperature and high temperature, reasonable in cooling speed, less in pollutants and excellent in quenching effect.

Description

A kind of novel quenchant

Technical fieldThe present invention relates to the quenching medium technical field, specifically relate to a kind of novel quenchant.

Background technologyWhen metal is carried out quench treatment, metal works need to be heated to a certain proper temperature and keep for some time, immerse immediately fast cooling in the quenching media.Traditional quenchant has water, the aqueous solution, mineral oil, fused salt, molten alkali etc.Novel quenchant has polyvinyl alcohol water solution and three glass gall solution etc.

Water is the stronger quenchant of cooling power.The source is wide, price is low, stable components is not perishable.Shortcoming is at C curve " nose " district (about 500～600 ℃), and water is in the steam film stage, cools off soon not, can form " soft spots "; And in the martensite transformation temperature district (300～100 ℃), water is in boiling stage, cools off too soon, easily makes the martensitic transformation excessive velocities and produces very large internal stress, causes workpiece deformation even cracking.When water temperature raises, contain in the water and sneak into insoluble impurity (such as oil, soap, mud etc.) in more gas or the water, all can significantly reduce its cooling power.

In water, add an amount of salt and alkali, after making the high temperature workpiece immerse this heat-eliminating medium, separate out the crystal of salt and alkali and immediately explosion in the steam film stage, steam film is destroyed, the oxide skin of workpiece surface is also scraped, and can improve like this medium in the cooling power of high-temperature zone.Its shortcoming is that the corrodibility of medium is large.

The general mineral oil that adopts of oil is such as machine oil, transformer oil and diesel oil etc.Machine oil is general to adopt No. 10, No. 20, No. 30 machine oil, oil number larger, and viscosity is larger, and flash-point is higher, and cooling power is lower, the corresponding raising of use temperature.The shortcomings such as oil product exists speed of cooling slow, and quenching effect is poor and inflammable.

Polyvinyl alcohol massfraction commonly used is the aqueous solution between 0.1%～0.3%, and cooling power is between water and oil altogether.When workpiece was quenched into this solution, workpiece surface formed one deck steam film and layer of gel film, and two membranes makes the heated parts cooling.After entering boiling stage, film breaks, work-piece cools is accelerated, when reaching low temperature, the polyvinyl alcohol gel film forms again again, and work-piece cools speed descends again, so this solution is low in high and low warm area cooling power, high in middle warm area cooling power, good cooling characteristic is arranged.

Three glass gall solution are comprised of 25% SODIUMNITRATE, 20% Sodium Nitrite, 20% saltpetre, 35% water.Because the salt crystal is separated out, and the broken steam film of going back forms, cooling power is close to water when high temperature (650～500 ℃).When low temperature (300～200 ℃) because very high concentrations, poor fluidity, cooling power is close to oil, so it can replace water-oily interrupted quenching.

Given this, for the difference that adapts to basic, normal, high temperature in the heat treatment process changes, guarantee the quality stability of heat treated part, need a kind of novel quenchant of invention badly.

Summary of the inventionDefective in view of prior art exists the objective of the invention is to provide a kind of novel quenchant, at low temperature, middle temperature, high temperature cooling ability height, speed of cooling is reasonable, pollutent is few, and quenching effect is desirable, can be used for place of water, oil, salt, alkali multimedium quenching medium.

For achieving the above object, the technology used in the present invention solution is: the moiety of novel quenchant is:

SODIUMNITRATE 25%;

Sodium Nitrite 20%;

Saltpetre 20%;

Polyvinyl alcohol 2%;

Sodium-chlor 3%;

Water 30%.

The novel quenchant of the present invention can be used for place of water, oil, salt, alkali multimedium quenching medium,, at low temperature, middle temperature, high temperature cooling ability height, speed of cooling is reasonable, and pollutent is few, and quenching effect is desirable, is a kind of new technology with promotional value.

EmbodimentEmbodiment of the present invention is:

The moiety of novel quenchant is:

SODIUMNITRATE 25%;

Sodium Nitrite 20%;

Saltpetre 20%;

Polyvinyl alcohol 2%;

Sodium-chlor 3%;

Water 30%.

Claims (1)

1. novel quenchant, it is characterized in that: the moiety of novel quenchant is SODIUMNITRATE 25%; Sodium Nitrite 20%; Saltpetre 20%; Polyvinyl alcohol 2%; Sodium-chlor 3%; Water 30%.