SU973642A1

SU973642A1 - Method for heat treating of welded joints

Info

Publication number: SU973642A1
Application number: SU813241534A
Authority: SU
Inventors: Юрий Михайлович Лебедев; Владимир Николаевич Лазарев
Original assignee: Николаевский Ордена Трудового Красного Знамени Кораблестроительный Институт Им.Адм. С.О.Макарова
Priority date: 1981-01-29
Filing date: 1981-01-29
Publication date: 1982-11-15

Description

Изобретение относитс к термической обработке и может йыть использовано при локальной обработке сварных соединений высоколегированных сталей мартенситного и мартенситноферритного классов с мартенситом высокой устойчивости.The invention relates to heat treatment and may be used in the local processing of welded joints of high-alloy steels of martensitic and martensite-ferrite classes with high-resistance martensite.

Известен способ термической обработки сварных соединений, включающий нагрев до температуры (30 40С ) с последующим замедленным охлаждением до температуры А - (30 40«С )С1.The known method of heat treatment of welded joints, including heating to a temperature of (30 40C), followed by slow cooling to a temperature of A - (30 40 "C) C1.

Обнако подобна термическа обработка не приводит в стал х указанного класса к заметному распаду мартенсита и не устран ет хрупкости сварного соединени и склонности к образованию трещин при дешьнейшем охлаждении.However, such a thermal treatment does not lead to the steels of this class to a noticeable decomposition of martensite and does not eliminate the brittleness of the welded joint and the tendency to form cracks with the cheapest cooling.

Наиболее близким к предлагаемому по технической сущности вл етс способ термической обработки сварных соединений, заключающийс в охлаждении сварного шва до температуры Ау. и импульсном нагреве до температуры 5 Aj..3TOT способ позвол ет в значительной мере уменьшить возможность образовани холодных трещин 2.The closest to the proposed technical essence is the method of heat treatment of welded joints, which consists in cooling the weld to the temperature Ay. and pulsed heating to a temperature of 5 Aj. 3.TOT method significantly reduces the possibility of cold cracks 2.

Однако способ не обеспечивает эксплуатационной стойкости к ударным нагрузкам шва и околошовнрй зоны,However, the method does not provide operational resistance to shock loads of the seam and near-zone,

Целью изобретени вл етс устранение возможности образовани холодных трещин и обеспечени высокой ударной в зкости сварного шва и околошовной зоны.The aim of the invention is to eliminate the possibility of the formation of cold cracks and the provision of high impact toughness of the weld and heat-affected zone.

Поставленна цель достигаетс The goal is achieved

10 тем, что согласно способу, включающему охлаждение после сварки, ускоренный нагрев и охлаждение, охлаждение после сварки производ т до температуры образовани / 50% мартен15 сита, но не ниже 150С, нагревают в межкритическом интервале температур , охлаждают до 100-150°С и вновь нагревают до температуры Aj. (50 - 100°С ) с последующим охлгикде20 нием на воздухе.10 by the fact that, according to the method including cooling after welding, accelerated heating and cooling, cooling after welding is carried out to the formation temperature of / 50% marten15 sieve, but not lower than 150 ° C, heated in the intercritical temperature range, cooled to 100-150 ° C re-heated to temperature Aj. (50 - 100 ° С) with subsequent cooling in air.

Нагрев и охлаждение производ т многократно.Heating and cooling are performed multiple times.

Claims

Cooling the welded joint to a temperature not lower than 2 ensures the formation of cold cracks from occurrence. Subsequent heating in the intercritical temperature range crushes the grain and promotes the formation of metastable austenite, and cooling to 100–150 ° C also avoids brittle fractures. Heating to an AC temperature (50–100 ° C) reduces the weld seam and raises its toughness. The welded joint of steel 20 after welding is cooled to a temperature of OralC (Tg for steel 20 is). This is followed by heating to SeOilO C, cooling to 1501–20 ° C and heating to 770 i. The mechanical properties of the welded joint from steel 2j13 after heat treatment according to the proposed method and the prototype are given in the table. Without heat treatment 550 Prototype t2 (double heating to) 320 The proposed 280 method is carried out on an HDTV installation with a frequency of 2500 Hz at a rate of 140 ° C / s, however, such heat treatment can be carried out by direct current passage, as well as during electron beam welding. 1. The method of heat treatment of welded joints from martensitic and martensitic-ferritic steels, including cooling after welding, accelerated heating and cooling, characterized in that, in order to prevent the formation of cold cracks and impact strength of the welded joint, cooling after welding t to the formation temperature / 50% martensite, but not lower than 150 ° C, then heated in the intercritical temperature range, cooled to 100-150 ° C. And again heated to temperature A - (50-100 ° C) followed by cool the air, according to claim 2.Sposob. 1, differing ayusch and also to the fact that heating and cooling is repeatedly m. Sources of information taken into account in the examination 1. A. Shchetanov. Local pulse tempering of welded joints, MITOM No. 6, 1973.

2. Authors certificate USSR 466289, CL. C 21 D 9/50, 1975.,