CN100359036C

CN100359036C - Cast steel for bearing parts in mechanical lifting system and its making process

Info

Publication number: CN100359036C
Application number: CNB2004100462280A
Authority: CN
Inventors: 赵旭平; 刘洪泽; 尹永晶; 陈彦平; 赵治洲; 周国星; 刘国友; 王芬兰
Original assignee: Sinopec Henan Petroleum Exploration Bureau Nanyang Petroleum Machinery Factory
Current assignee: Sinopec Henan Petroleum Exploration Bureau Nanyang Petroleum Machinery Factory
Priority date: 2004-06-07
Filing date: 2004-06-07
Publication date: 2008-01-02
Anticipated expiration: 2024-06-07
Also published as: CN1706979A

Abstract

The present invention relates to a cast steel for bearing components in mechanical lifting systems and a productive method thereof. The cast steel materials adopt low or medium carbon Cr-Ni-Mo series having chemical compositions (weight percentage): 0.15 to 0.30 of C, 0.60 to 1.10 of Mn, 0.3 to 0.8 of Si, 0.4 to 1.1 of Ni, 0.4 to 1.1 of Cr, 0.15 to 0.40 of Mo, at most 0.025 of S and at most 0.025 of P; at most 0.50 of Cu, at most 0.10 of W and at most 0.003 of V are taken as residual elements, and residual element total quantity is at most 0.60. Production is orderly carried out according to the following steps: (1). an intermediate frequency furnace or an electric arc furnace is used for smelting steel according to chemical composition requirements; (2). sand is cast, and mechanical property test rods adopt equivalent physa test rods; (3). castings and the test rods are processed by normalising, interrupted hardening and tempering in the same furnace; the furnace temperature of the normalising is from 880 to 920 DEG C, heat preservation lasts for 160 to 240 minutes, and air cooling is carried out; the furnace temperature of the interrupted hardening is from 860 to 900 DEG C, heat preservation lasts for 160 to 240 minutes, and oil cooling is carried out after water cooling for 30 to 60 seconds; the furnace temperature of the tempering is from 600 to 640 DEG C, heat preservation lasts for 240 to 320 minutes, and then air cooling is carried out; and (4). the steel castings adopt a non-destructive inspection mode.

Description

The mechanical means lifting system load bearing element manufacture method of cast steel

Technical field

The present invention relates to the manufacture method of a kind of mechanical means lifting system load bearing element, be specially adapted to of the manufacturing of petroleum machinery equipment lifting system bearing part with cast steel material with cast steel.

Background technology

Requirements such as crucial bearing part, particularly petroleum machinery lift technique bearing part such as coupler body, hook tube, suspension ring, elevator have higher comprehensive mechanical performance in the mechanical means lifting system at present.(the petroleum industry press distribution of the main lift technique SY/T5208-2000 of petroleum well workover standard, calendar year 2001s 12 publication), the explanations such as (distribution of petroleum industry press were published in 1992 9) of elevator SY/T5041-92 standard is used for making casting coupler body, hook tube and elevator at present, the suspension ring material mainly is ZG34Cr2Ni2Mo, ZG35CrMo." casting handbook cast steel. the 2nd edition. Chinese China Machine Press 2002.8 has put down in writing the mechanical property (seeing the following form) of these two kinds of materials, these two kinds of materials are because carbon content is higher, toughness index is low, and ZG35CrMo intensity is also on the low side, and the casting dimension of producing is big, and weight is also big, though ZG34Cr2Ni2Mo intensity height, but except toughness was not high, because it is many to contain noble elements such as Cr, Ni, cost was than higher.These two kinds of materials all can not satisfy low temperature impact properties Akv 〉=42 J (20 ℃) requirement that API API Spec 8C standard (version in 1997) proposes foundry goods in addition.Along with the integrating with of world market, research meets international standard, it is very necessary with cast steel material to obtain the lift technique load bearing element that meets the international Valuation Standard of API.

ZG35CrMo, ZG34Cr2Ni2Mo main Mechanical

Material	σs≥	Akv(J)≥
Material	σs≥	Akv(J)≥	ZG35CrMo	540	32 (normal temperature)
ZG34Cr2Ni2Mo	700	32 (normal temperature)	ZG35CrMo	540	32 (normal temperature)

In " Cr-Ni-Mo wearable cast steel and the application on tup " literary composition that periodical " foundry engieering ", 1999 the 6th periodicals are stepped on, disclose a kind of composition and thermal treatment process of Cr-Ni-Mo wearable cast steel, its mass percent consists of 0.30%～0.70%C; 0.50%～1.50%Si; 0.6%～1.5%Mn; 1.0%～3.0%Cr; 0.4%～2.0%Ni; 0.2%～1.0%Mo; ≤ 0.05%S, P, its thermal treatment process is selected quenching temperature, quenchant and tempering temperature and is controlled, and makes this kind steel have higher hardness and matches with better flexible, is used to make tup and has improved work-ing life.But the mechanical property that table 1 and Fig. 3 provide from literary composition, if when this kind steel was applied in the mechanical means lifting system crucial bearing part, its impelling strength particularly low temperature impact properties far can not satisfy low temperature impact properties Akv 〉=42 J (20 ℃) requirement that API API Spec 8C standard (version in 1997) proposes foundry goods.

Summary of the invention

The problem that the present invention need solve is to propose the manufacture method of a kind of mechanical means lifting system load bearing element with cast steel material, the comprehensive mechanical performance that the cast steel material that this manufacture method is produced has high strength, high tenacity, can satisfy low temperature impact properties Akv 〉=42 J (20 ℃) requirement that U.S. API Spec 8C standard proposes foundry goods, solve the low problem of cast steel material toughness index of now using.

The object of the present invention is achieved like this:

Mechanical means lifting system load bearing element adopts low middle carbon Cr-Ni-Mo to be Chemical Composition such as following table with cast steel material:

Chemical Composition (massfraction, %)

C	Mn	Si	Ni	Cr	Mo	S	P	Residual element
								Residual element				Cu	W	V	Total amount
								0.15 0.30	0.60 1.10	0.3 ～ 0.8	0.4 ～ 1.1	Cu	W	V	Total amount	0.4 ～ 1.1	0.15 0.40	≤ 0.035	≤ 0.035	≤ 0.50	≤ 0.10	≤ 0.03	≤ 0.60

Mechanical means lifting system load bearing element of the present invention is with cast steel processing step manufacturing in the following order:

1, smelting technology: adopt intermediate frequency furnace or electric-arc furnace steelmaking, strict control Chemical Composition.

2, casting technique: equivalent circular Kiel coupon is adopted in sand mold casting, mechanical property coupon.

3, thermal treatment process: adopt normalizing+double quenching and tempering

Normalizing: 880～920 ℃ of furnace temperature are incubated 160～240 minutes, air cooling.

Double quenching: 860～900 ℃ of furnace temperature, be incubated 160～240 minutes, water-cooled is oil cooling after 30～60 seconds.

Tempering: 600～640 ℃ of furnace temperature are incubated 240～320 minutes, air cooling.

4, non-destructive test(ing)(NDT): carry out the non-destructive test(ing)(NDT) of foundry goods ray or carry out the casting ultrasonic non-destructive test(ing)(NDT) or carry out the non-destructive test(ing)(NDT) of foundry goods magnetic according to standard GB/T9444 according to standard GB/T7233 according to standard GB/T5677.

Experiment condition and method by national Specification are tested test result to the mechanical property coupon: be organized as tempered sorbite, and hardness HB280-320, σ s 〉=655MPa, σ b 〉=795MPa, δ 5 〉=15%, φ 〉=40%, Akv 〉=42J (20 ℃).

Beneficial effect of the present invention is:

1, low-temperature impact toughness height: adopt low middle carbon Cr-Ni-Mo steel, can guarantee hardening capacity and intensity index, can guarantee toughness index because its carbon content is low again.

2, intensity height: adopt the double quenching technology, both guaranteed hardening capacity and intensity index, can reduce distortion and cracking again.

The invention will be further described below in conjunction with embodiment.

Embodiment

Bore with oil that to repair equipment lifting system bearing part elevator be example with the manufacture method of cast steel:

Elevator is selected to see the following form with the Chemical Composition of cast steel:

Chemical Composition (massfraction, %)

C	Mn	Si	Ni	Cr	Mo	S	P	Residual element
								Residual element				Cu	W	V	Total amount
								0.24～ 0.30	0.70～ 1.00	0.5～ 0.8	0.5～ 0.8	Cu	W	V	Total amount	0.5～ 0.8	0.15～ 0.30	≤ 0.025	≤ 0.025	≤ 0.50	≤ 0.10	≤ 0.03	≤ 0.60

The processing step manufacturing in the following order of this cast steel material:

1, smelting technology: adopt intermediate frequency furnace, select the electrolytic nickel of Ni 〉=99.9% for use, make steel by the Chemical Composition requirement.

2, casting technique: sand mold casting, ceramic network is filtered during casting, and the mechanical property coupon adopts equivalent circular Kiel coupon.

3, thermal treatment process: foundry goods and coupon are carried out with stove normalizing+double quenching+temper;

The car type furnace normalizing: 900 ± 10 ℃ of furnace temperature are incubated 160～200 minutes, air cooling;

The car type furnace double quenching: 880 ± 10 ℃ of furnace temperature, be incubated 160～220 minutes, water-cooled is oil cooling after 30～60 seconds;

The tempering of whirlwind tempering stove: 620 ± 10 ℃ of furnace temperature are incubated 240～280 minutes, air cooling;

4, by the requirement of GB/T5677 radiographic test steel casting is carried out the ray non-destructive test(ing)(NDT).

Empirical tests: material of the present invention has high strength, high tenacity, is specially adapted to product application such as elevator, hook block, and product weight is compared than ZG35CrMo material elevator and alleviated about 10%.

Claims

1, a kind of mechanical means lifting system load bearing element manufacture method of cast steel, described mechanical means lifting system load bearing element adopts low middle carbon Cr-Ni-Mo to be with cast steel, Chemical Composition (massfraction, %) content C=0.15～0.30, Mn=0.60～1.10, Si=0.3～0.8, Ni=0.4～1.1, Cr=0.4～1.1, Mo=0.15～0.40, S≤0.035, P≤0.035, residual element Cu≤0.50, W≤0.10, V≤0.03, residual element total amount≤0.60 is characterized in that: the processing step that comprises following order:

1. smelting technology: adopt intermediate frequency furnace or electric arc furnace to make steel by the Chemical Composition requirement;

2. casting technique: equivalent circular Kiel coupon is adopted in sand mold casting, mechanical property coupon;

3. thermal treatment process: adopt foundry goods and coupon are carried out with stove normalizing+double quenching+temper;

Normalizing: 880～920 ℃ of furnace temperature are incubated 160～240 minutes, air cooling;

Double quenching: 860～900 ℃ of furnace temperature, be incubated 160～240 minutes, water-cooled is oil cooling after 30～60 seconds;

Tempering: 600～640 ℃ of furnace temperature are incubated 240～320 minutes, air cooling;

4. steel casting is adopted ray non-destructive test(ing)(NDT) or ultrasonic flaw detection or magnetic non-destructive test(ing)(NDT).

2, the manufacture method of cast steel according to claim 1 is characterized in that: in the described processing step:

1. smelting technology: adopt intermediate frequency furnace, select the electrolytic nickel of Ni 〉=99.9% for use;

2. casting technique: ceramic network is filtered during casting;

3. thermal treatment process:

The car type furnace normalizing: 900 ± 10 ℃ of furnace temperature are incubated 160～200 minutes;

The car type furnace double quenching: 880 ± 10 ℃ of furnace temperature are incubated 160～220 minutes;

The tempering of whirlwind tempering stove: 620 ± 10 ℃ of furnace temperature are incubated 240～280 minutes;

4. steel casting is carried out the ray non-destructive test(ing)(NDT).