The welder of martensite stainless steel art what is the point

Of martensite stainless steel solder what is craft point


Martensite stainless steel has tendency of intense empty temper by dipping in water, its welding line and organization of the position after heat affects the solder of the area are martensite, produce cold crack very easily. Solder to avoid cold crack and improvement the mechanical function of contact, should take the step such as temper of the high temperature after warm-up, postheat and solder.

The warm-up before 1 solder

Solder martensite stainless steel, special using what be the same as composition with mother capable person to solder when material, to prevent cold cracking, warm-up needs before solder. Warm-up temperature is chosen commonly in 200 ～ 329 ℃ , had better not prep above martensite begins transition temperature. The quantity that contain carbon is the mainest factor of affirmatory warm-up temperature, the volume that contain carbon is high, warm-up temperature should a few taller. The other factor that affects choice warm-up temperature still has sort of metal of material ply, fill, solder method, cabined degree etc. Contain carbon to be less than 0.1% when but not warm-up, also have proposal warm-up temperature, be like warm-up 450 ℃ of 400 ～ , but the adverse effect that should notice high temperature warm-up is brought. The quantity that contain carbon is more than 0.2% when, it is relatively difficult to solder, outside dividing warm-up, need maintains the temperature between the layer.

The temperature before the temper after 2 solder

Do not answer after workpiece solder from solder temperature warms up directly undertake temper is handled. Because soldering,the austenite in the process may transform not completely, if temper warms up instantly after solder, meeting occurrence carbide precipitates along austenite crystal boundary and austenite change of Xiang Zhuguang body, produce the organization with bulky grain, reduce tenacity badly. Because should make weldment cooling before this temper, make welding line and the austenite that heat up influence area basic be decomposed. To the component part with small stiffness, can cold to fire of the farewell after room temperature. To the structure of big ply, should contain carbon particularly when the volume is higher, need to use more sophisticated technology: Solder hind is cold to 100 ～ 150 ℃ , heat preservation 0.5 ～ 1.0h, heat next to temper temperature.

3 solder postheat is handled

The purpose of the heat treatment after solder is to reduce welding line and hardness of hot influence area, improve its plasticity and tenacity, decrease at the same time solder leftover stress. The heat treatment after solder includes temper and complete anneal. Be in only to get low hardness, if need the machine after solder to add man-hour, just use complete anneal, annealing temperature is 830 ～ 880 ℃ , the furnace after heat preservation 2h is cold to 595 ℃ , next air is cold. Stainless steel of tall chromic martensite is in commonly in quench + the attune of temper solders below qualitative condition, temper of high temperature of the classics after solder is handled, make solder contact has good mechanical performance. If solder below anneal condition, inhomogenous martensite organization still can appear after solder, whole weldment still needs to be handled character through tone, make contact has even property.

The choice of temper temperature should get used to connect of project project butt joint mechanical function and be able to bear or endure the requirement of corrode sex. Temper temperature is chosen commonly in 650 ～ 750 ℃ , at least heat preservation 1h, next air is cold. Temper temperature not Ying Taigao, prevent once more austenite change. Solder to what high temperature uses the structure often uses higher temper temperature. The carbide with the more separate out when high temperature temper, to be able to bear or endure corrode sex is adverse. To basically using Yu Naishi's structure, should undertake microtherm is spent eliminate stress anneal.

Martensite stainless steel solders commonly the method has solder of arc of argon of manual arc welding, tungsten pole and Co2 solder. The hand wants arc welding is Martens low stainless steel the most commonly used method in soldering, use when soldering with composition welding rod with mother capable person, type of welding rod coating should be low nitrogen model, must pass before solder be as high as 350 ～ the high temperature of 400 ℃ is roast, so that comb-out water is divided, reduce diffusible hydrogen content and reduce cold crack sensitivity. Short arc solder is used when soldering, in order to reduce air hole. When solder hind cannot have heat treatment, use austenite welding electrode to solder, solder the standard consults the requirement of austenite welding electrode.
Solder of arc of tungsten pole argon is used at thin plate to solder commonly, use dc anode sex. Of solder of arc of tungsten pole argon solder quality is better, cold crack tendency is lesser, general thin plate need not warm-up.
The connect of Co2 solder contains hydrogen the amount is small, cold crack inclination is little, can use inferior warm-up temperature.


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